7. simplify (2x – 2y)(2y + 8) = ?

a. 4xy + 16x – 4y2 – 16y
b. 4xy – 16x – 4y2 – 16y
c. 4xy – 4y2
d. 4xy + 16x + 4y2 + 16y

4xy + 16x - 4y^2 - 16y (Answer A)

Step-by-step explanation:

Factoring 2 out of both binomials inside parentheses makes this problem a bit simpler to handle:

(2x – 2y)(2y + 8) = 2(x - y)(2)(y + 4) = 4(x - y)(y + 4)

Multiplying out the two binomial terms results in:

4 (xy + 4x - y^2 - 4y)

Performing the indicated multiplication results in:

4xy + 16x - 4y^2 - 16y.

This agrees with Answer A.  Please note, however, that y2 must be written as y^2 (the square of y) to be proper.

x=-2

infinite number of lines, so there is an infinite number of equations.

step-by-step explanation:

there are an infinite number of line that passes through the point (-2,5)

x=-2   is one line that passes through the point

y = 5 is another line that passes through the point

(these two lines are perpendicular to each other).

since the number of   numbers are infinite and the slope is the ratio of two numbers,(change in y over change in x) we can have an infinite number of slopes.     our only condition is that it passes through the point (-2,5)

3x + 4y -25 =0 represents the amount of change sianna should recieve