Question

Persamaan kuadrat akar
dik : a= 2 b=7 c= -4
rumus x1 pangkat 2 + x2 pangkat 2 =

Answer 1

X₁² + x₂²
= (x₁+x₂)² - 2x₁x₂
= (-b/a)² - 2(c/a)
= (-7/2)² - 2(-4/2)
= 49/4 - (-4)
= 49/4 + 4
= (49+16)/4
= 65/4

Answer 2

X1 + x2 = -b/a = -7/2
   x1.x2 = c/a = -4/2 = 2

x1^2 + x2^2  = (x1+x2)^2 + 2x1x2
                   = (-7/2)^2 + 2.2
                   = 49/4 + 4
                   = (49+16)/4
                   = 65/4
                   = 16 1/4