Problems from Incomplete quadratic equations

Development:

1) Since there is only one term with $x$, we can isolate the unknown directly: $$3x^2-12=0$$ $$3x^2=12$$ $$x^2={\displaystyle \frac{12}{3}}=4$$ $$x=\pm \sqrt{4}=\pm 2$$ $$x_1=2\text{and}{x}_2=-2$$

2) Since there is no independent term, we can take the common factor of the $x$: $$x^2-x=0$$ $$x(x-1)=0$$ $$x_1=0;\text{and}x-1=0\to x_2=1$$

3) Since there is only one term with $x$, we can isolate the unknown directly: $$1-4x^2=-8$$ $$1+8=4x^2$$ $${\displaystyle \frac{9}{4}}=x^2$$ $$x={\displaystyle \frac{\pm \sqrt{9}}{\pm \sqrt{4}}}={\displaystyle \frac{\pm 3}{\pm 2}}$$ $$x_1={\displaystyle \frac{3}{2}}\text{and}{x}_2={\displaystyle \frac{-3}{2}}$$

Solution:

1) $x_1=2\text{and}{x}_2=-2$

2) $x_1=0\text{and}{x}_2=1$

3) $x_1={\displaystyle \frac{3}{2}}\text{and}{x}_2={\displaystyle \frac{-3}{2}}$

Hide solution and development