Chapter 2 - Section 2.1 - Linear Equations in One Variable - Exercise Set - Page 56: 77

All real numbers

We are given the equation $2x+3=2x+3$. Without simplifying, we can tell that this equation will have all real numbers as solutions because both sides are identical. Therefore, we can plug in any real number value for x, and both sides will still be equal. Example, $x=0$ $2\times0+3=2\times0+3=3$ Example, $x=3$ $2\times3+3=2\times3+3=9$