Given the linear function [tex]f(x) = -5x + 10[/tex], what is the value of [tex]x[/tex] if [tex]f(x) = 35[/tex]?

A. [tex]\dot{x}=-165[/tex]
B. [tex]x=-9[/tex]
C. [tex]x=-5[/tex]
D. [tex]x=185[/tex]



Answer :

To determine the value of \( x \) for which \( f(x) = 35 \) given the linear function \( f(x) = -5x + 10 \), follow these steps:

1. Start with the equation defined by the function:
[tex]\[ f(x) = -5x + 10 \][/tex]

2. Set \( f(x) \) equal to 35:
[tex]\[ -5x + 10 = 35 \][/tex]

3. Isolate the term involving \( x \) by subtracting 10 from both sides of the equation:
[tex]\[ -5x + 10 - 10 = 35 - 10 \][/tex]
Which simplifies to:
[tex]\[ -5x = 25 \][/tex]

4. Solve for \( x \) by dividing both sides by -5:
[tex]\[ x = \frac{25}{-5} \][/tex]
Which simplifies to:
[tex]\[ x = -5 \][/tex]

Given that \( x = -5 \) is the solution, we can check our answer by substituting \( x = -5 \) back into the original function:
[tex]\[ f(-5) = -5(-5) + 10 = 25 + 10 = 35 \][/tex]
Indeed, \( f(x) = 35 \) when \( x = -5 \).

Thus, the correct value of \( x \) is:
[tex]\[ \boxed{-5} \][/tex]