Question

Explain why the equation 5|x|-7=7 has only one solution.

Answer 1

According to the condition, this equation has two solutions: -14/5 and 14/5.

Short explanation:

5|x|=14; ⇔ |x|=14/5; ⇒

$\left[\begin{array}{ccc}x= -\frac{14}{5} \\x= \frac{14}{5} \\\end{array}$

PS. it's correct, if to substitute the values of 'x' into the condition/equation.