2x-5y=13

Posted on Jun 16, 2013

4x+7=2(x-3)

4x+7=2x-6

4x-2x=-7-6

2x = -13

2x/2 = -13/2

x = -6.5

Posted on Mar 03, 2009

Paul 3 years younger to his friend peter. In seven years, the product of their ages would be 5 more than the product of their ages 5 years ago. How old are they now?

Posted on Oct 31, 2008

Let's break this down into a few parts first.

Slope intercept form is otherwise known as y = mx + b, where m is the slope and b is the y-intercept.

Perpendicular means that the two lines will intersect each other at a 90 degree angle. In math terms, their slopes will be negative reciprocals of each other.

Starting with y + 4 = 1/4(x -7), putting into slope intercept form, y = mx + b, m = 1/4 and b=-7/4 -4.

Since it is perpendicular, it must have a slope that is a negative reciprocal. The slope of the original line is 1/4, so the multiplying it -1, we get -1/4, and taking the reciprocal, we get -4. So the slope of the perpendicular line is -4.

So, y = -4x + b, but we don't know what the value of b is. To determine this, we know the point (-4,7) is on the line that we are trying to find, so we can substitute it into the equation and calculate b to make it work.

Every time we see an x we put in -4 and every time we see a y, we put in 7.

y = -4x + b

7 = -4(-4) + b

7 = 16 + b

subtract 16 from both sides

7 - 16 = 16 + b - 16

-9 = b

Now substitute this into the equation.

y = -4x + -9

Putting it into correct form, we get y = -4x - 9.

Let's check it to see if it is correct.

It has a slope of -4, so it is perpendicular to y=1/4x - 5 3/4.

Is the point (-4,7) on the line? Let's substitute it in to see if it is on the line.

Again, everywhere we see an x, we put in -4 and everywhere we see a y we put in 7.

y= -4x - 9

7 = -4 (-4) - 9

7 = 16 - 9

7 = 7

Sorry for the very long explanation, I was being overly thorough, but after you do a few of them, you will be able to knock them off in minutes.

Good luck,

Paul

Slope intercept form is otherwise known as y = mx + b, where m is the slope and b is the y-intercept.

Perpendicular means that the two lines will intersect each other at a 90 degree angle. In math terms, their slopes will be negative reciprocals of each other.

Starting with y + 4 = 1/4(x -7), putting into slope intercept form, y = mx + b, m = 1/4 and b=-7/4 -4.

Since it is perpendicular, it must have a slope that is a negative reciprocal. The slope of the original line is 1/4, so the multiplying it -1, we get -1/4, and taking the reciprocal, we get -4. So the slope of the perpendicular line is -4.

So, y = -4x + b, but we don't know what the value of b is. To determine this, we know the point (-4,7) is on the line that we are trying to find, so we can substitute it into the equation and calculate b to make it work.

Every time we see an x we put in -4 and every time we see a y, we put in 7.

y = -4x + b

7 = -4(-4) + b

7 = 16 + b

subtract 16 from both sides

7 - 16 = 16 + b - 16

-9 = b

Now substitute this into the equation.

y = -4x + -9

Putting it into correct form, we get y = -4x - 9.

Let's check it to see if it is correct.

It has a slope of -4, so it is perpendicular to y=1/4x - 5 3/4.

Is the point (-4,7) on the line? Let's substitute it in to see if it is on the line.

Again, everywhere we see an x, we put in -4 and everywhere we see a y we put in 7.

y= -4x - 9

7 = -4 (-4) - 9

7 = 16 - 9

7 = 7

Sorry for the very long explanation, I was being overly thorough, but after you do a few of them, you will be able to knock them off in minutes.

Good luck,

Paul

Apr 03, 2016 | Calculators

I think of a balanced scale in my mind when I start these questions. What ever I do to one side, I have to do to the other side to keep it balanced. It starts balanced and I have to keep it balanced.

-(7-4x)=9

(-1) (-1)(7-4x) = 9 (-1) multiply both sides by -1 to get rid of the negative sign

7-4x=-9

7-4x-7=-9-7 subtract 7 from both sides

-4x = -16

-4x = -16

----- ----- divide both sides by -4 to get x by itself

-4 -4

x=4

Check by putting our answer in the original equation and see if the left side is equal to the right side.

Left Side Right Side

-(7-4(4)) 9

-(7-16)

-(-9)

9

Left side = right side

-(7-4x)=9

(-1) (-1)(7-4x) = 9 (-1) multiply both sides by -1 to get rid of the negative sign

7-4x=-9

7-4x-7=-9-7 subtract 7 from both sides

-4x = -16

-4x = -16

----- ----- divide both sides by -4 to get x by itself

-4 -4

x=4

Check by putting our answer in the original equation and see if the left side is equal to the right side.

Left Side Right Side

-(7-4(4)) 9

-(7-16)

-(-9)

9

Left side = right side

Mar 16, 2015 | Calculators

Let us backtrack so as to better jump.

An algebraic expression may contain one or several**algebraic terms**, separated by a plus sign or a or a minus and a sign.

Each algebraic term is the product of a constant coefficient and a power of some variable, or the powers of several variables.

Example of an algebraic term 3(x^2)(y^6)....

**If the exponents of the various powers are positive integers, the term is called a monomial. **In short no square roots, or fractionary powers of the variables appear in monomials. Thus 2/x, 3SQRT(x), or 1/x^5 are not monomials.

Finally, a polynomial is an**algebraic expression** made up of one or more monomials.

Example P(X)=(1/3)X^7-(SQRT(5)*X^4+ 16X-25 is a polynomial of degree 7 in the indeterminate/variable X

Q(X,Y)= 3(X^3)*Y^2 + 4X-5Y+10 is a polynomial of degree 5 in the variables X and Y.

An algebraic expression may contain one or several

Each algebraic term is the product of a constant coefficient and a power of some variable, or the powers of several variables.

Example of an algebraic term 3(x^2)(y^6)....

Finally, a polynomial is an

Example P(X)=(1/3)X^7-(SQRT(5)*X^4+ 16X-25 is a polynomial of degree 7 in the indeterminate/variable X

Q(X,Y)= 3(X^3)*Y^2 + 4X-5Y+10 is a polynomial of degree 5 in the variables X and Y.

Oct 01, 2014 | Calculators

All you can do with this polynomial is

To factor (x^2-3x-4) look for the divisors of -4 whose sum is -3

You cannot do that on your calculator because is does not have a Computer Algebra System or CAS.

Oct 02, 2013 | Casio FX82MS Scientific Calculator

if you mean {7(2)2+[(3-2)-4x(3)]2} or 7(2)2+[(3-2)-4x(3)]2

{28+[(1)-12]2}

{28+[-12]2}

{28+-24}

=4

or if it was 4x not 4 times

{7(2)2+[(3-2)-4x(3)]2}

28+[(1)-12x]2

28+-24x

=-28x+28

{28+[(1)-12]2}

{28+[-12]2}

{28+-24}

=4

or if it was 4x not 4 times

{7(2)2+[(3-2)-4x(3)]2}

28+[(1)-12x]2

28+-24x

=-28x+28

Jun 12, 2013 | Calculators

Yes it can be keyed in.

To enter the X, use the ALPHA followed by ). To enter the = sign, you use [ALPHA][CALC].

To use the calculator to SOLVE an equation you must enter the equation, then press [SHIFT][CALC] to (SOLVE). You will be prompted to solve for X. Follow it from there.

As to the case you show, the constant terms will drop and you are left with 26X=0, and the solution is X=0.

**Note: The calculator cannot do algebra with letter symbols. It does not have a Computer Algebra System or CAS.**

To enter the X, use the ALPHA followed by ). To enter the = sign, you use [ALPHA][CALC].

To use the calculator to SOLVE an equation you must enter the equation, then press [SHIFT][CALC] to (SOLVE). You will be prompted to solve for X. Follow it from there.

As to the case you show, the constant terms will drop and you are left with 26X=0, and the solution is X=0.

Mar 28, 2012 | Casio Calculators

Sorry the calculator is unable to perform symbolic algebra calculations. Fortunately for you there is no need for the calculator. Use the special product (idemtity) (a-b)(a+b)=a^2-b^2 with a=2X and b=10

Aug 07, 2011 | Casio FX-115ES Scientific Calculator

Strange. The calculator comes with a Getting Started manual. In any event you can download an electronic copy from education.ti.com.

From the associated icon of the calculator, I surmise that you have TI Nspire without the CAS (Computer Algebra System). Unfortunately, this version of the Nspire cannot perform symbolic algebra. It will use the distributive property by itself if you feed it expressions without letter symbols. If you type in expressions with symbols, all symbols must have a value stored in them. The exception is instances where you are trying to solve an equation (or a systems of linear equations).

From the associated icon of the calculator, I surmise that you have TI Nspire without the CAS (Computer Algebra System). Unfortunately, this version of the Nspire cannot perform symbolic algebra. It will use the distributive property by itself if you feed it expressions without letter symbols. If you type in expressions with symbols, all symbols must have a value stored in them. The exception is instances where you are trying to solve an equation (or a systems of linear equations).

Aug 03, 2011 | Texas Instruments TI-Nspire Graphic...

3(4x-7) = 15
4x-7 = 45
4x = 52
x = 13

May 12, 2011 | Texas Instruments TI-83 Plus Calculator

Just plug in one side of the equation and find the answer. Then plug in the other side and compare answers.

Feb 19, 2008 | Texas Instruments TI-89 Calculator

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