Use the substitution method to solve the system of equations. choose the correct ordered pair.
3x- y=3
y=2x +2

a. (2,6)
b. (5,12)
c. (4,10)
d.(3,8)

Explanation:

Start with the first equation. We'll plug in y = 2x+2

3x - y = 3

3x - ( y ) = 3

3x - ( 2x+2 ) = 3 replace y with 2x+2

3x - 2x - 2 = 3 distribute the negative through to all terms inside

x-2 = 3   combine like terms

x-2+2 = 3+2 add 2 to both sides

x = 5

Use this x value to find the value of y. The easiest equation to use is the one in which y is already isolated for us

y = 2x+2

y = 2*5+2 replace x with 5

y = 10+2

y = 12

Though we can use the other equation as well

3x-y = 3

3*5-y = 3 replace x with 5

15 - y = 3

15-y-15 = 3-15 subtract 15 from both sides

-y = -12

y = 12 multiply both sides by -1, or change the signs of both sides

We get the same result for y.

The solution is (x,y) = (5,12) meaning that the graphs of the two original equations cross at this point.

to find the unit price, we must figure out the cost of one item (in this case one dish towel).   to do this, we divide the total price ($7.92) by the number of items bought (for this problem it is 8, because there are eight dish towels in one pack).  

$7.92/8 = $0.99

therefore, the unit price, or the price of one dish towel, is $0.99.

hope this !