Упростить. 1) 6+4a-5a+a-7a 2)5(x-2)-6(x+3)-3(2x-9)
1)6-7а 2)5х-10-6х-18-6х+27=-7х-1
1) 6+4a-5a+a-7a=6-7a 2) 5(x-2)-6(x+3)-3(2x-9)=5x-10-6x-18-5x+27=5x-6x-5x-10-18+27=-6x-1