Answer:
$8.00
Step-by-step explanation:
Let's set up the equation first.
What do we know:
1. We have 6 friends spliting the costs of the gifts
2. After purchasing the gifts they have $42 in change
3. They originally had $90 to spend.
Equation:
6f + $42 = $90
Next: Subtract the $42 from each side and we are left with:
6f = $48
Divide both sides by 6 and we are left with
f = $8
Since f represented the cost each friend spent our answer is $8.00
Answer:
yes
Step-by-step explanation:
Answer:
(x) =
Step-by-step explanation:
let y = f(x), then rearrange making x the subject
y = 
x + 4 ( subtract 4 from both sides )
y - 4 = x ( multiply both sides by 5 to clear the fraction )
5y - 20 = x
Change y back into terms of x with x = (x) , then
(x) = 5x - 20
F^1(-2) = 2(-2) = -4
f(-4) = 1/2 * -4 = -2
f(f^-1(x)) = x so answer is -2
