All you have to do is plug in the numbers for x.
7. y = 4ˣ, x = 3 --> y = 4⁽³⁾ --> y = 4 * 4 * 4 --> y = 64.
8. f(x) = 2 * 3ˣ, x = 5 --> f(5) = 2 * 3⁽⁵⁾ --> f(5) = 2 * 243 --> f(5) = 486.
9. h(t) = 60 * 1.07^t, t = 8 --> h(8) = 60 * 1.07⁸ --> h(8) = 60 * 1.718186179831921 --> h(8) = 103.091171
10. y = 5 * 7ˣ, x = 0 --> y = 5 * 1 --> y = 5
