Question

Use only the digits 0 - 9 and the decimal and the negative sign, if needed, to fill in the blank. If f(x) = 2x + 9, then f(-1) = _____.

Answer 1

7

Explanation:

f(x) = 2x + 9

Put x as -1.

f(-1) = 2(-1) + 9

Multiply both terms 2 and -1.

f(-1) = -2 + 9

Add the terms -2 and 9.

f(-1) = 7

Answer 2

the answer would be 7