3(x +5)=7-5x , 4(x-9)=3(x-8) , 7(3-2x)=15(1-x) не могу решить. зарание

3(x +5)=7-5x ,
3x + 15 = 7 - 5x
3x + 5x = 7 - 15
8x = - 8  / : 8
x = - 1

4(x-9)=3(x-8) ,
4x -36 = 3x - 24
4x -3x = - 24 + 36
x = 12

7(3-2x)=15(1-x)
21 - 14x = 15 - 15x
-14x + 15x = 15 - 21
x = - 6