6t^3 x 6t^3

A.12t^3
B.12t^6
C.36t^6
D.36t^9

-3(4x+5)

A.7x+15
B.7x-15
C.-12x-15
D.-12x+15

5k^2(-6k-2k+6)

A.-30k^3+3k^2+30k
B.30k^4-10k^3+11k^2
C.-k^4+3k^3+11k^2
D.30k^4-10k^3+30k^2

(-4x).9x^2

A.-36^3
B.-36x^2
C.5x^3
D.5x^2

2 answers

My answers are cbaa
-3(4x+5)
= -12x - 15 which is C

5k^2(-6k-2k+6)
= -30k^3 - 10k^3 + 30k^2
which is none of them.
I suspect a typo, why would you have two like terms in the bracket ?

the others are correct