The input value that produces the same output value for the two functions is -6
In order to determine the value of x that produces the same function, we will equate the expressions to have:
f(x) = g(x)
2/3x + 7 = 2x + 15
Collect the like terms
2/3x - 2x = 15 - 7
2x-6x/3 = 8
-4x/3 = 8
Cross multiply
-4x. = 3(8)
-4x = 24
x = -6
Hence the input value that produces the same output value for the two functions is -6