40x + 8x²= 0
Move the 8x² over the the left side of 40x, so that the equation is in correct order.
So, now we have :
8x² + 40x = 0
Factorize the left side.
What goes into both 8x² and 40x? 8x do! :)
8x(x + 5) = 0
Set the factors to equal zero.
8x = 0 AND x + 5 = 0
8x = 0
Divide both sides b 8.
x = 0
x + 5 = 0
Subtract 5 from both sides.
x = -5
So, x = 0 AND x = -5
(0, -5)
~Hope I helped!~