3x +7 = –12x -18
3x + 12 = -18 - 7
15x = - 25 /:15
x = - [tex]\frac{25}{15}[/tex]
x = - [tex]\frac{5}{3}[/tex]
x = [tex]-1 \frac{2}{3}[/tex]
2(10 –5x) = 3(2 –x) -4(x-1)
20 - 10x = 6 - 3x - 4x + 4
20 - 10x = 10 - 7x
-10x + 7x = 10 - 20
-3x = - 10 /: (-3)
x = [tex]\frac{10}{3}[/tex]
x = [tex]3\frac{1}{3}[/tex]