2(х+2)-5(2-х)-(5+2)х-1= 2x+4-10+5x-5x-2x-1=0x-7
2(х+4)-4(5-х)-(4+2)х-3= 2x+8-20+4x-4x-2x-3=
0x-15
1) б
2) 1.3406+7*(31655-18975)=92 166
2.20кг 450г+870г=21кг 320г
.....=sin(90-18)+cos(270-48)-sin(12)=cos(18)-sin(12)=cos(18)-(sin(48)+sin(12))=cos(18)-2sin(30)cos(18)=cos(18)*(1-1)