Question

The tables represent the functions f(x) and g(x).

Which input value produces the same output value for the two functions?

x = –12
x = –9
x = –6
x = –3

Answer 1

x = -6 has the same output for both functions

Explanation:

Here, we want to get the x value that has the same y-value for both functions

We can simply get this by substituting

Let’s take it one after the other

if x = -12

f(x) = 2/3(-12) + 7

= -8 + 7 = -1

2(-12) + 15 = -9

This is incorrect

for x = -9

g(x) = 2/3(-9) + 7

= -6 + 7 = 1

f(x) = 2(-9) + 15 = -3

for x = -6

g(x) = 2/3(-6) + 7 = 3

f(x) = 2(-6) + 15 = 3

So as we can see our answer is x = -6