You earn $35 for washing 7 cars. you earn $ for washing 4 cars?

Most of the information's that are required for solving this question is already given. it is important to read the question minutely and then solving the problem will become easy.
The amount earned by washing 7 cars = $35
Then
The amount earned by washing 1 car = (35/7) dollars
                                                             = 5 dollars
So
The amount earned by washing 4 cars = (5 * 4) dollars
                                                               = 20 dollars
So you earn $20 for washing 4 cars. I hope this is the answer you were looking for and the procedure is also clear to you.

Answer: b 2 = 1.

step-by-step explanation: given equation a = h(b 1+b 2)

also we are given values of a, h and b 1 as :

a = 16, h = 4, and b 1 = 3.

in order to solve it for b 2, we need to plug the given values of   a, h and b 1 .

therefore, plugging values of   a, h and b 1   in given equation, we get

16 = 4( 3 + b 2)

first dividing both sides by 4, we get

4 = 3 + b 2

subtracting 3 from both sides, we get

4 -3 = 3 -3 + b 2

1 = b 2.

therefore, b 2= 1.