4(3x+2y)+5(7a+6x)+7y+3a=
12х+8у+35а+30х+7у+3а= = 42х+15у+38а
12x+8y+35a+30x+7y+3a=42x+15y+38a
=12x+18y+35a+30x+7y+3a=42x+15y+38a