Question

(x^2-4 x)^2 + 2(x^2-4x)-15=0
u= x^2-4x
rv= u^2+2u-15=0
D=64
u1= 3
u2= -5
Dus x^2-4x=3 of x^2-4x =-5


D= (-4)*-4 * (1) * (-3)
D=28
Why can't I calculate this futher? What did I do wrong?

Answer 1

What are you trying to do?

Answer 2

Oh you're just solving for x?

Answer 3

bi quadratic compare

Answer 4

I wana solve this (x^2-4 x)^2 + 2(x^2-4x)-15=0