Answer:
They charged <u>$6</u> for washing and <u>$2</u> for vacuuming the car.
Step-by-step explanation:
Let the charge of washing a car be 'x'.
And also let the charge of vacuuming a car be 'y'.
Now according to question, Trisha raised $38 washing 5 cars and vacuuming 4 cars.
So framing the above sentence in equation form, we get;

Again according to question, Byron raises $28 by washing 4 cars and vacuuming 2 cars.
So framing the above sentence in equation form, we get;

Now multiplying equation 2 by '2', we get;

Now we subtract equation 1 from equation 3 and get;

Now substituting the value of 'x' in equation 1, we get;

Hence They charged <u>$6</u> for washing and <u>$2</u> for vacuuming the car.