a) -y +13=9+2y б)19-11x=14-x
-y+2y=-13+9 -11x+x=-19+14
y=-4 -10x=-5/ :(-10)
x=0.5
в)1.7a+2=1.7-0.3a г)11+0,5b=4 -3b
1.7a+0.3a=1.7-2 0.5b+3b=4-11
2a=-0.3/:2 3.5b=-7/ :3,5
a=-0.15 b=-2
д)1-m=1+1.2m е)-1.6x+2=14+0.8x
-m-1.2m=1-1 -1.6x-0.8x=14-2
-2.2m=0 -2.4x=12/:2.4
m=0 x=-5