Part 1
Plug in x = 8 and simplify
h(x) = -2x-10
h(8) = -2(8)-10
h(8) = -16-10
h(8) = -26
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Part 2
Replace h(x) with 14. Follow PEMDAS in reverse to solve for x.
h(x) = -2x-10
14 = -2x-10
14+10 = -2x
24 = -2x
24/(-2) = x
-12 = x
x = -12
If x = -12, then h(x) = 14
In other words, h(-12) = 14
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Check:
h(x) = -2x-10
h(-12) = -2(-12)-20
h(-12) = 24-20
h(-12) = 14