Solve Equations That Are Quadratic in Form
Solve the equation by making an appropriate substitution.
-$2 x ^ { 1 / 2 } - 3 x ^ { 1 / 4 } - 20 = 0$
A) $\{ 256 \}$
B) $\left\{ 256 , \frac { 625 } { 16 } \right\}$
C) $\{ - 4 , - 5 \}$
D) $\left\{ 4 , - \frac { 5 } { 2 } \right\}$

Question

Quizplus · Accepted Answer

By substituting $ u = x^{1/4} $, the equation becomes $ 2u^2 - 3u - 20 = 0 $. Solving this quadratic equation gives $ u = 5 $ or $ u = -2 $. Since $ u = x^{1/4} $, $ x = 256 $ is the only valid solution.

Solve Equations That Are Quadratic in Form Solve the Equation 2x1/2−3x1/4−20=02 x ^ { 1 / 2 } - 3 x ^ { 1 / 4 } - 20 = 02x1/2−3x1/4−20=0

Solve Equations That Are Quadratic in Form
Solve the Equation $2 x ^ { 1 / 2 } - 3 x ^ { 1 / 4 } - 20 = 0$