Question

Use the quadratic formula to find the solutions to the quadratic equation below. Check all that apply. 5x2-X-4 = 0 A. -4/5 B. 5/4C. 2/3 D. 1 E. -1 F.3/2​

Answer 1

Hi

5x²-x-4 = 0  

Δ= (-1)² - 4*5*(-4)

Δ =  1 -4*-20

Δ = 1  +80

Δ = 81  

√Δ=  9

as Δ ≥ 0 , so 2 solutions exist in R

S1 is :    ( 1+9) /2*5  =   10/10 = 1

s2 =      (1 -9)/2*5 =  -8/10 = -4*2 /2*5  = -4/5

Corrects answers are  A  and  D