Evaluate the following:

Question

-2y^2 for y=3,-3 and 9c-2d for c=1,d=1/2 and c=3,d=-2.

Answer 1

1) The first expression -2y ^2

For y  = 3

Substitute the y  value in above expression.

-2y ^2 = -2(3)^2 = -2*9 = -18

For y  = -3

Substitute the y  value in above expression.

-2y ^2 = -2(-3)^2 = -2*9 = -18

2) The second expression 9c - 2d

For c = 1,  d = 1/2

Substitute the c ,d  values in above expression.

9c - 2d  = 9(1) - 2(1/2) = 9 - 1 = 8

For c  = 3,  d  = -2

Substitute the c ,d values in above expression.

9c - 2d  = 9(3) - 2(-2) = 27 + 4 = 31.