Question

Megan and Sam together take 12 minutes to wash a car. Washing the car by herself Megan took 21 minutes. How long would it take Sam to wash the car?

Answer 1

\[\frac1x + \frac{1}{21} = \frac1{12}\]Solve for x.

Answer 2

Can you do that?

Answer 3

I'm guessing no??

Answer 4

Woah sorry umm k gimme a sec

Answer 5

x = -9?

Answer 6

First step: Find a common denominator and set up a proportion.\[\frac{x + 21}{21x} = \frac{1}{12}\]Step 2: Cross Multiply
12(x + 21) = 21x
Step 3: Solve for x
12x + 252 = 21x
9x = 252
x = ?