Question

What value of x makes f(x) = -2 if f(x) = 3.4x - 7.1

Answer 1

Option C

For x = 1.5 we get f(x) = -2

Solution:

Given function is:

$f(x) = 3.4x - 7.1$

We have to find the value of "x" so that f(x) = -2

Substitute f(x) = -2 in given function

$-2 = 3.4x - 7.1$

Solve for "x" by moving the constants to one side and variables to other side

$3.4x = -2 + 7.1\\\\3.4x = 5.1\\\\ \text{Divide both the sides of equation by 3.4 }\\\\x = \frac{5.1}{3.4}\\\\x = 1.5$

For x = 1.5 we get f(x) = -2

We can verify by substituting x = 1.5 in given function

$f(1.5) = 3.4(1.5) - 7.1\\\\f(1.5) =5.1-7.1\\\\f(1.5) = -2$

Thus for x = 1.5 we get f(x) = -2