Question

Which expressions, when evaluated with z = 8, are negative in value?

Answer 1

To find out which equation is negative when you plug in z=8, then plug it in and find out! :D

A) –2z – 14 = -2(8)-14 = -16-14 = -30

-2x-14 is negative when z = 8. So A is one possible answer :)

B) –25 + 4z = -25 + 4(8) = -25 + 32 = 7

7 is positive when z = 8, so B is not a correct answer.

C) –2z + 15 = -2(8) + 15 = -16 + 15 = -1

-1 is negative when z  8, So C is another correct answer choice.

D) 30 – 3z = 30 - 3(8) = 30 - 24 = 6

6 is positive when z=8, So D is not a correct answer.

To summarize, your answer would be A and C.

Answer 2

$z=8\\\\put\ the\ value\ of\ "z"\ to\ the\ expressions:\\\\A.\\-2z-14\to-2(8)-14=-16-14=-30 < 0\ \boxed{YES}\\B.\\-25+4(8)=-25+32=7 > 0\ \boxed{NO}\\C.\\-2z+15\to-2(8)+15=-16+15=-1 < 0\ \boxed{YES}\\D.\\30-3z\to30-3(8)=30-24=6 > 0\ \boxed{NO}$