Answer :
Answer:
B. -4
Step-by-step explanation:
We want to find x such that f(x)=18.
We need to therefore solve 9x+54=18 forx.
9x+54=18
Divide both sides by 9:
(9x+54)/9=18/9
9x/9+54/9=18/9
Simplify:
x+6=2
Subtract 6 on both sides:
x=2-6
Simplify
x=-4.
So f(-4) should have value 18.
Let's check.
f(x)=9x+54
f(-4)=9(-4)+54
f(-4)=-36+54
f(-4)=18
So the answer is B.
Answer:
The value of x when [tex]f(x)=18[/tex] is -4
Step-by-step explanation:
Expression : [tex]f(x)=9x+54[/tex]
We are given that [tex]f(x)=18[/tex]
We are supposed to find the value of x when [tex]f(x)=18[/tex]
So, Expression : [tex]f(x)=9x+54[/tex]
Substitute [tex]f(x)=18[/tex]
[tex]18=9x+54[/tex]
[tex]18-54=9x[/tex]
[tex]-36=9x[/tex]
[tex]\frac{-36}{9}=x[/tex]
[tex]-4=x[/tex]
So, option B is true
Hence the value of x when [tex]f(x)=18[/tex] is -4