-30-29-28-27-26-25-24-23-22-21-20-19-18-17-16-15-14-13-12-11-10-9-8-7-6-5-4-3-2-1+1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20+21+22+23+24+25+26+27=
-30-29-28 (остальное сократится)= -59-28= -87
{x/10 - y/5 = 0 | * 10
{5x + y = 7 | *6
{x - 2y = 0
{10x + y = 42
{x = 2y
{20y + y = 42
{x = 2y
{21y = 42
{x = 2y
{y = 2
{x = 4
{y = 2
А=468*18:12
а=702
с=1000:2*8
с=4000
<span>3 (х-2)-5 (х+1,8)=2
3x-6-5x-9=2
-2x-15=2
-2x=2+15
-2x=17
x=</span> - [/tex]\frac{17}{2}
1) 5m-(3m+5)+(2m-4) = 5m-3m-5+2m-4 = 4m-9
2) -5*( Х+3)+4(Х-2)-6(2Х+1) = -5Х-15+4Х-8-12Х-6 = -13Х-29 = 13Х+29