A plumber charges $50 to visit a house plus $80 for every hour of work. Define a variable and write an expression to represent the total cost of hiring a plumber.

The point a is at –2 and the point b is at 7. marissa would like to divide this line segment in a 4: 3 ratio, and she would like to use the formula x = (x2 – x1) + x1. what values should she substitute into the formula? a = a + b = x1 = x2 =