g^2+4g-32=0

g² + 4g - 32  =  0

(Find two number that, when multiplied together, give you 32 and when you subtract one from the other, you get 4  --->  They will be 8 and 4.)

(g + 8)(g - 4)  =  0

Either g + 8  =  0   --->   g  =  -8

Or      g - 4  =  0   --->   g  +  4