What is the best approximation of the solution to the system to the nearest integer values? 2x-5y=-20
3x+2y=20

2x -  5y = -20 ⇒   4x -  10y = -40
3x + 2y =  20 ⇒ 15x + 10y = 100
                                    19x = 60
                                     19     19
                                        x = 3³/₁₉
                               2x - 5y = -20
                        2(3³/₁₉) - 5y = -20
                            6⁶/₁₉ - 5y = -20
                          - 6⁶/₁₉           - 6⁶/₁₉
                                    -5y = -26⁶/₁₉
                                     -5       -5
                                       y = 5⁵/₁₉
                                 (x, y) = (3³/₁₉, 5⁵/₁₉)
The best approximation of the solution to the system of the nearest integer values are (4, 6), or (x, y) ≈ (4, 6).

Well if she earned the same amount per hour the hours can be added. 2.25 + 3.25 = 5.5 hours. To get the rate of earning per hour you would then divide the total made by the total time worked. 42/5.5 = $7.64 approximately.