Often statements become clearer if they are rewritten using variables and quantifiers. This can often be done in slightly different ways. Try rewriting each of the following using variables and quantifiers. Every real number is either positive, negative, or zero.
Some triangles are equilateral.
The sum of two rational numbers is rational. Some integers are perfect squares. The product of two rational numbers is rational. The square root of any irrational number is irrational. The cube root of any integer is rational.