1) distribute the coefficient into the parentheses having it look like this:
(-5+25x)+(-40x-10)=-4x-8x
2) then, you want to combine all the like terms so you get:
-15-15x=-12x
3) then you add the x to the other side:
-15= 3x
4) divide by 3 to get te x alone and you’re done!
-5=x