The owner of a hair salon charges $20 more per haircut than the assistant. Yesterday the assistant gave 12 haircuts. The owner gave 6 haircuts. The total earnings from the haircuts were $750. How much does the owner charge for a haircut? Solve by writing and solving a system of equations?

X: $55

Let the owner's charge be $x

then the assistant's charge is x-20

6x + 12(x-20) = 750
6x + 12x - 240 = 750
18x = 990
x = 55

To solve this problem using a system of equations, let's denote the price charged by the assistant as "x" dollars per haircut. Therefore, the price charged by the owner would be "x + 20" dollars per haircut.

Now, let's set up the system of equations based on the given information:

1) The assistant gave 12 haircuts, so the total earnings from the assistant's haircuts would be 12x dollars.

2) The owner gave 6 haircuts, so the total earnings from the owner's haircuts would be 6(x + 20) dollars.

We also know that the total earnings from all the haircuts were $750. Therefore, we can set up another equation:

3) 12x + 6(x + 20) = 750

Now, let's solve the system of equations:

Expanding the equation (3):

12x + 6x + 120 = 750
18x + 120 = 750

Moving 120 to the other side:

18x = 750 - 120
18x = 630

Dividing both sides by 18:

x = 630 / 18
x = 35

Therefore, the assistant charges $35 per haircut. Since the owner charges $20 more than the assistant, the owner charges $35 + $20 = $55 per haircut.