#1
8x-5y
1/8m-1/4m+1/2m-3/4m=1/8m-2/8m+4/8m-6/8m=-3/8m
#2
0,05b
b=-3,6
-3,6*0,05=-0,18
b=20/3
1/20*20/3=1/3
#3
(-1,2a+2,5b)4-3(3,2a-0,6b)=-4,8a+10b-9,6a+1,8b=-14,4a+11,8b
2/3(9/5-5/4a)-7/3(6/5-5/14a)=
6/5-5/6a-14/5+5/6a=-8/5=-1,6
#4
-10xy
6,6ab
4/7(-3/4n)7/9=-(3/7)7/9=-1/3
#5
-7/12x+2/3x-1/4x=-7/12x+8/12x-3/12x=
-1/6x
#6
9/10(2/5-5/3m)-1/5(4/5-15/2m)=
9/25-3/2m-4/25+3/2m=1/5=0,2
#7
2(5x-4y)-3(4x-y)=10x-8y-12x+3y=-2x-5y
x=-5
y=0,8
-2*(-5)-5*0,8=10-4=6
#8
1/2Y-2/3Y-5/9Y=7/12
9/18Y-12/18Y-10/18Y=7/12
-13/18Y=7/12|:(-13/18)
Y=7/12*(-18/13)=-21/26
1/5Z-2/3Z=-28/100
3/15Z-10/15Z=-7/25
-7/15Z=-7/25|:(-7/15)
Z=0,75
#9
3(0,4X+7)-4(0,8X-3)=3
1,2X+21-3,2X+12=3
-2X=3-23
-2X=-20|:(-2)
X=10
9/2(7/15X+2/9)-77/100(8/11X-3/7)=-7/4
21/10X+1-56/100x+33/100=-1,75
2,1x-0,56x=-1,75-0,44-1
1,54x=-3,19|:1.54
x=-319/154