)1) -10(2a-3b)+6b-a 2) 2(-4x-5)-3(x+8) 3) 7(8x+6)-4(2x-8) 4) 5a(-2b)×8 5) -(y+b)+(a-b+y)

1) -10(2a-3b)+6b-a=-20а+30b+6b-a=36b-21a; 2) 2(-4x-5)-3(x+8)=-8x-10-3x-24=-11x-34; /// 3) 7(8x+6)-4(2x-8)=56x+42-8x+32=48x+74; /// 4) 5a(-2b)×8=-10ab*8=-80ab; 5) -(y+b)+(a-b+y)=-y-b+a-b+y=a-2b