1) -x = -5/ 13
-x = -5/13 / (-1)
x = 5/13
2) x = 9/12
x = 3/4 = 0,75 (разделили обе части на 3)
3) x = -2 /(-4)
x = 1/2 = 0,5 (ибо "-" делить/умножить "-" = "+")
4) -2х - 5х = 30 - 16
-7х = 24 / (-7)
x = -24/7
5) -3х + 5х = -4 - 2
2х = -6 / 2
x = -3
6) -x = 12 / (-1)
x = -12
7) 8x - 2x - 3x = 9
3x = 9 / 3
x = 3
8) x = 1/3 + 1/4
x = 7/12
9) x = 1/2 + 2/1
x = 3/2
10) x = 2,5 - 7/9
x = 5/2 - 7/9
x = 31/18