Question

if alpha and beta are the roots of equation 2x^2+5x-4=0 then find the value of alpha^2+beta^2-3alpha-3beta​

Answer 1

Answer:

alpha^2+beta^2-3 alpha-3 beta =17.75

Step-by-step explanation:

equation = 2 x^2+5 x-4

→ alpha + beta =-b/a

                        =-5/2

→ alpha * beta =c/a

                        =-4/2 =-2

thus, alpha^2+beta^2-3 alpha-3 beta

→ (alpha +beta)^2 - 2*(alpha*beta )- 3(alpha +beta)

→ (-5/2)^2 - 2*-2 - 3*(-5/2)

→ 25/4 + 4 + 15/2

→(25 + 16 + 30)/4

→71/4

→17.75