Question

\ \textgreater \ 0" alt="5x^{2}+|x+1|\ \textgreater \ 0" align="absmiddle" class="latex-formula">
Can someone explain me how this is done? My book says that the answer is R (all numbers), but i get [-1; infinity) and two other roots.

Answer 1

5x² + |x+1| > 0
5x² + x + 1 > 0
x+1 > 0 because it came from absolute
5x² > 0 because it’s squared

When you try a number you should put it in the original equality
5x² + |x+1|