Explain, in complete sentences, how you would use the substitution method to solve the following system of equations. Provide the solution to the system.
5x - y = -1
7x - 3y = 13

Question

anonymous · Answer

I would take the first equation, and add y to both sides, then add 1 to both sides, in order to get y by itself. By doing this, I would find that y = 5x + 1. Knowing this, I would take the second equations and substitute (5x + 1) for every y. I would then add like terms and have -8x - 3 = 13, and in order to solve this for x, I would add 3 to both sides, and then divide both sides by -8. I would find that x = -2, and then plug -2 into the first equation for every x. By doing this, I would find that -10 - y = -1, and by adding 1 and y to both sides, I would find that y = -9. From all this work, I would find the completely solution to be x = -2 and y = -9.