the first equation of the system is mutiplied by 2,by what number would you mutiply the second equation to eliminate the x variable by adding. first:6x - 5y =21 4x+7y= 15 when i did the promblem i got 2 answers -3 or -2 im not sure which one
2*6 = 12
-3*4 = -12
12+ (-12) = 0