Answer:
To find f-¹(x) of f(x) equate f(x) to y
That's
f(x) = y
So we have

Next interchange the variables that's x becomes y and y becomes x
That's

Next make y the subject
Cross multiply
We have
4y - 7 = 10x
Move -7 to the right side of the equation
4y = 10x + 7
Divide both sides by 4
We have the final answer as

So

Hope this helps you
Answer:
Step-by-step explanation:
Answer: x=15
Step-by-step explanation: Since 3x+5 is equal to 50, you can write 3x+5=50, and 3x=45, x=15.
Part a: 30 gallons (i think)
part b: 220