Solve
-16x^(-2)+2x=0
answer=2 or 0
and
-9x^2+1=0
but how do you do it?
million thanks!
Hello, BabyMilo!
Solve: .$\displaystyle -16x^{-2}+2x\:=\:0$
Answer: $\displaystyle 2\text{ or }0$ . . . . not true
but how do you do it?
We have: .$\displaystyle 2x - 16x^{-2} \:=\:0$
Multiply by $\displaystyle x^2\!:\;\;2x^3 - 16 \:=\:0$
Factor: .$\displaystyle 2(x^3-8)\:=\:0 \quad\Rightarrow\quad x^3 \:=\:8 $
Therefore: .$\displaystyle x \:=\:2$