Answer:
10x²-3x-4=0
we write -3x as a difference
10x²+5x-8x-4=0
factor 5x into 10x²+5x =5x(2x+1)
factor -4 into -8x-4 =-4(2x+1)
we write the equation
5x(2x+1)-4(2x+1)=0
factor
(2x+1)(5x-4)=0
solve the zero product equation
2x+1=0⇔2x=-1⇔x=-1/2
5x-4=0⇔5x=4⇔x=4/5
x= -1/2 ou 5/4 Q(x)=0