Question

Given g(x)=5x+4, solve for x when g (x)=9

Answer 1

g( 1 ) = 9

Explanation:

Remember that in linear functions expressed in the function notation, g(x), this means that for any allowed value of x, we can use the equation to find the corresponding value of g(x) or y (output). Thus, the linear function g(x) = 5x + 4 is essentially the same as expressing the given equation as: y = 5x + 4.

Solution:

Given the linear function, g(x) = 5x + 4, we can solve for x when g(x) = 9 by substituting the value of the output, g(x) = 9, into the function.

g(x) = 5x + 4

9 = 5x + 4

Subtract 4 from both sides:

9 - 4 = 5x + 4 - 4

5 = 5x

Divide both sides by 5 to solve for x:

`\large\mathsf{(5)/(5)\:=\:(5x)/(5)}`

x = 1

Therefore, when g(x) = 9, the value of x = 1. Another way of expressing this is: g( 1 ) = 9.