Question

Which factors can be multiplied together to make the trinomial 5x^2+8x-4

Answer 1

Answer:

Step-by-step explanation:

hello :

5x²+8x-4  quadratic expression when : a = 5  and  b=8  and  c= -4

∆ = b²-4ac        ∆ = 8²-4(5)(-4) = 64 +80 = 144 = 12²

X1 = ( -b -√∆)/2a       X1 = (-8-12)/10 = -20/10= -2

X2 =(-b+√∆)/2a       X2 = (-8+12)/10 = 4/10 = 2/5

us factorisation : a(X-X1)(X-X2)

5x²+8x-4= 5(x+2)(x-2/5) = (x+2)(5x-2)

you can verify ;  (x+2)(5x-2) = 5x²-2x+10x-4 = 5x²+8x-4