Question

x to the 4 minus 8x squared plus 7=0

Answer 1

\[x^4 -8x^2 + 7 = 0\]

this factorises to

\[(x^2 - 7)(x^2 - 1)=0\]

which gives

\[x = \pm \sqrt{7}... and... x = \pm 1\]

Answer 2

x^4 - 8x ^2 + 7 = 0
let x^2 = X
X^2 - 8X + 7 = 0
(X - 7)(X - 1) = 0
X = 7 or 1

can you continue with this?