Accepted Answer
[tex]x-(-8\cdot x)=x+7\\\\x-(-8x)=x+7\\\\x+8x=x+7\\\\9x=x+7\\\\9x-x=x+7-x\\\\8x=7\\\\8x:8=7:8\\\\x=\frac{7}{8}[/tex]
Accepted Answer
You have said that [ x - (-8x) = x + 7 ] .Note that [ - (-8x) ] = 8xSo the equation may be written as [ x + 8x = x + 7 ] .Add up the 'x's on the left side: 9x = x + 7Subtract 'x' from each side: 8x = 7Divide each side by 8 : x = 7/8