Answer:
[tex]x=-1[/tex]
Step-by-step explanation:
The equation for slope is:
[tex]Slope=\frac{y_2-y_1}{x_2-x_1}[/tex]
In this case, x would represent, [tex]y_2[/tex]. Therefore...
[tex]Slope=\frac{y_2-y_1}{x_2-x_1}\\1=\frac{x-(-8)}{5-(-2)}\\1=\frac{x+8}{5+2}\\1=\frac{x+8}{7}\\\\Multiply\ 7\ to\ both\ sides\\\\7=x+8\\\\\ Subtract\ 8\ from\ both\ sides\\\\x=-1[/tex]