Solve.
-$x ^ { 4 } - 50 x ^ { 2 } + 49 = 0$
A) $- 1,1 , - 7,7$
B) $- i , i , - 7 i , 7 i$
C) $- 1,1 , - 7 i , 7 \mathrm { i }$
D) 1,49

Question

Quizplus · Accepted Answer

This equation can be solved by substituting $y = x^2$, turning it into a quadratic equation $y^2 - 50y + 49 = 0$. Solving this gives $y = 1$ and $y = 49$, which when substituted back as $x^2 = 1$ and $x^2 = 49$, gives the solutions $x = \pm 1$ and $x = \pm 7$, respectively.

Solve - x4−50x2+49=0x ^ { 4 } - 50 x ^ { 2 } + 49 = 0x4−50x2+49=0

Solve
- $x ^ { 4 } - 50 x ^ { 2 } + 49 = 0$