Answer: Y= -5 and X= 1
Step-by-step explanation:
Linear equations, huh? Okay, well we'll subtract for this problem. 7x minus 7x is nothing, so x is all cancelled out. Negative y minus 3y is -4y. And 12 minus -8 is 20, since the two negatives become a positive. So we have -4y = 20, so y equals -5. Great, so now we plug in y in one of the equations. I'll chose the top one. Our new equation is: 7x+5=12. Subtract both sides by 5, and we have 7x=7. Well, this means that x equals 1, therefore giving y equals -5, and x equals 1.
Aight, let's check. Plug in both variables for both equations. We get 7+5=12, and 7-15= -8