The solution to the system of equation below is (−2, −1). 2x − 3y = −1 11x − 9y = −13 when the first equation is multiplied by −3, the sum of the two equations is equivalent to 5x = −10.

We are given with two equations 2x − 3y = −1 and 11x − 9y = −13. The problem says that when the first equation is multiplied by -3 which results to -6x + 9y = 3, the sum of the resulting equation and the second one is equal to 5x = -10. We verify this: -6x + 11x = 5x while -9 y and 9 y cancels out. 3+-13 equals -10. Hence the total is really 5x = - 10.

J= r + 9 because since jessica rode 9 more miles than roger, you add 9 miles to rogers mileage.