Which expression is equivalent to -21?
A. 9-(-12)
B. 9+(-12)
C. -9+12
D. -9-12

D. -9-12=-21

Step-by-step explanation:

Which expression is equivalent to -21?

A. 9-(-12) = 9+12 = 21

B. 9+(-12)  = 9-12 = -3

C. -9+12 = -9+12 = 3

D. -9-12=-21

395.84

step-by-step explanation:

2πrh+2πr²

2 (pie)(radius)(height)+2(pie)(radius)^2

i can't see the picture : /