substitution method need help for home work
-3y = x...so we sub in -3y for x in the other equation-x + 7y = 70-(-3y) + 7y = 703y + 7y = 7010y = 70y = 70/10y = 7so we sub in 7 for y in either of the original equations to find x-3y = x-3(7) = x-21 = xso ur solution is (-21,7)