-4(3-b)-6=5(2a+1)+5 2(3b-4)+7=7(1-a)-10 -4(3-b)-6=5(2a+1)+5 -12+4b-6-5*(2a+1)-5=0 -18+4b-10a-5-5=0 -28+4b-10a=0 a=-2.8+0.4b 2(3b-4)+7=7(1-a)-10 6b-1-7+7a+10=0 6b+2+7a=0 6b+2+7*(-2.8+0.4b)=0 6b+2-19.6+2.8b=0 8.8b-17.6=0 b=17.6/8.8 b=2 -28+4b-10a=0 -28+4*2-10a=0 -20-10a=0 a=-20/10 a=-2