Exponents and Exponential Functions Unit Test

someone PLEASE oh PLEEEEEAAAASSSSEEEEE explain to me all of the answers cuz i just can't think straight, plus, mathematics are literally making mah brain go "FLOP"

HMMMM -(10)^-1
A. -1/10
B. -1/-1^10
C. 1/10
D. 10

(-7.4)^0

A. -1
B. -7.4
C. 0
D. 1

-1/a^-2
A. -a2
B. -2/a
C. -2a
D. a^2

5^4 x 5^7

A. 125^11
B. 15^11
C. 5^28
D. 5^11

Simplify this expression:

(3)^10 (3)^-9

A. 3
B. 1/3
C. 9^-90
D. 9

(t^8)^2

A. 2t^16
B. t^10
C. t^16
D. t^64

(5t^3)^-4

A. 625/t^12
B. 20/t^7
C. 1/625t^12
D. 1/20t^7

(ok i'm sorry if i don't write the rest of the questions/options, it's just my back is hurting from leaning to long and my fingers hurt for typing to long and my brain is burning up because of how many numbers and letters there are in this test......)

(IF YOU KNOW THE REST OF THE QUESTIONS AND OPTIONS PLEASE WRITE IT ALONG IN YOUR ANSWER!!! I NEED IT ASAP OR ELSE I'M GETTING AN F- IN MY GRADE ._.)