1) 9*(x+7)=-x

9x+63=-x

9x+x=-63

10x=-63

х=-63/10

x=-6,3

2) 5-2x=8x+9

-2x-8x=9-5

-10x=4

х=-0,4

3) x+9=-9x

х+9x=-9

10x=-9

x=-0,9