1) 3(2,5 – 2x) = 13,5 – 14x
7.5-6x=13.5-14x
-6x+14x=13.5-7.5
8x=6
x=6/8
x=0.75
2) 0,6y – 1,5 = 0,3(y – 4)
0.6y-1.5=0.3y-1.2
0.6y-0.3y=-1.2+1.5
0.3y=0.3
y=0.3/0.3
y=1
3) 0,5(4 – 2a) = a – 1,8
2-a=a-1.8
-a-a=-1.8-2
-2a=-3.8
a=-3.8/(-2)
a=1.9
4) 7(3 + x) = 2(x – 5) + 8
21+7x=2x-10+8
7x-2x=-2-21
5x=-23
x=-23/5
x=-4.6
5) –0,2(5 – 0,7x) + 0,02 = 1,4(x–1,6)
-1+0.14x+0.02=1.4x-2.24
0.14x-1.4x=-2.24+1-0.02
-1.26x=-1.26
x=-1.26/(-1.26)
x=1
6) 1,2(3b + 5) = 2(2,4b – 3,6)
3.6b+6=4.8b-7.2
3.6b-4.8b=-7.2-6
-1.2b=-13.2
b=-13.2/(-1.2)
b=11
7) 3,2(5x – 1) = 3,6x – 9,4
16x-3.2=3.6x-9.4
16x-3.6x=-9.4+3.2
12.4x=-6.2
x=-6.2/12.4
x=-0.5
8) 8(0,7x – 4) – 2(0,2x – 3) = – 39
5.6x-32-0.4x+6=-39
5.2x=-39+26
5.2x=-13
x=-13/5.2
x=2.5
9) –3(2,1z – 4)– 4,2 = 1,2(– 5z+ 0,5)
-6.3z+12-4.2=-6z+0.6
-6.3z+6z=0.6-7.8
-0.3z=-7.2
z=-7.2/(-0.3)
=24
10) 6,4(2 – 3y) = 6(0,8y – 1) + 6,8
12.8-19.2y=4.8y-6+6.8
-19.2y-4.8y=0.8-12.8
-24y=-12
y=-12/(-24)
y=0.5
4x-10x+11x=5-15
5x=10
x=2
Проверка:
5*2=10
10=10