Question

Two functions are shown in the table below.

Function 1 2 3 4 5 6
f(x) = −x2 + 4x + 12
g(x) = x + 8
Complete the table on your own paper, then select the value that is a solution to f(x) = g(x).
x = 3
x = 4
x = 5
x = 6

Answer 1

Given:
f(x) = - x² + 4x + 12
g(x) = x + 8

f(1) = -(1)² + 4(1) + 12 = -1 + 4 + 12 = -1 + 16 = 15
f(2) = -(2)² + 4(2) + 12 = -4 + 8 + 12 = -4 + 20 = 16
f(3) = -(3)² + 4(3) + 12 = -9 + 12 + 12 = - 9 + 24 = 15
f(4) = -(4)² + 4(4) + 12 = -16 + 16 + 12 = -16 + 28 = 12
f(5) = -(5)² + 4(5) + 12 = -25 + 20 + 12 = -25 + 32 = 7
f(6) = -(6)² + 4(6) + 12 = -36 + 24 + 12 = -36 + 36 = 0

g(1) = 1 + 8 = 9
g(2) = 2 + 8 = 10
g(3) = 3 + 8 = 11
g(4) = 4 + 8 = 12
g(5) = 5 + 8 = 13
g(6) = 6 + 8 = 14

f(x) = g(x) when x = 4
f(4) = g(4)
12 = 12