решите уравненияx-2/3=5/6 a0,4=4/15x-5/8=5/89/10c=3/20

X - 2/3 = 5/6
х = 5/6 + 2/3
х = 5/6 + 4/6
х = 9/6 = 1 3/6 = 1 1/2

a 0,4 = 4/15
0,4а = 4/15 0,4
0,4а 0,4 = 4/15 4/10
а = 4/15 10/4
а = 4/15 5/2
а = 2/3 = 0,6

x - 5/8 = 5/8
х = 5/8 + 5/8
х = 10/8 = 5/4 = 1 1/4

9/10 с = 3/20
9/10 1/с = 3/20
9/10с = 3/20
920 = 310
180с = 30
с = 6

1)x-2/3=5/6

x=5/6+2/3

x=3/2

2)a0,4=4/15

0,4a=4/15

a=2/3

3)x-5/8=5/8

x=5/8+5/8

x=5/4

4)9/10c=3/20

9/101/c=3/20

9/10c=3/20

180=30c

30c=180

c=6