Further Solving Quadratic Equations (Hidden Quadratics) (Edexcel A-Level Mathematics): Quizzes

To break complex equations into simpler pieces

$u = x^2$

$u = sqrt{x}$

$u = 3$

$x = pmsqrt{3}$

$(u + 10)(u - 2) = 0$

Square roots must be positive

$x = 4$

Both values of $u$ are negative

There are no real roots

Substitute a simpler variable for complex term

Substitute back to find $x$