Найдите корень уравнений: 1) (8х+3)-(10х+6)=9 2) 3,5 - х =8(х+2,8) 3) 0,3(6-2у) =4,5-0,7(у+9) 4)3/5(7/9x-1/3)=x-7/3

(8х+3)-(10х+6)=9
-2x -3 = 9
2x = -3 - 9
2x = -12
x = -6

3,5 - х =8(х+2,8)
3.5 - x = 8x + 22.4
8x + x = 3.5 - 22.4
9x = -18.9
x = -18.9/9
x = -2.1

0,3(6-2у) =4,5-0,7(у+9)
1.8 - 0.6y = 4.5 - 0.7y - 6.3
4.5 - 6.3 - 1.8 = -0.6y + 0.7y
0.1y = -3.6
y = -3.6 / 0.1
y = -36

3/5(7/9x-1/3)=x-7/3
21x/45 - 1/5 = x - 7/3
x - 21x/45 = 7/3 - 1/5
24x/45 = 32/15
x = 32 * 45 / (15 * 24)
x = 4