### Home > PC3 > Chapter 1 > Lesson 1.1.5 > Problem1-51

1-51.

Though it looks like the following equations are true, each of them is actually false. Confirm this by substituting simple numbers for the variables and doing the arithmetic. Note: Do not use $0$ or $1$; they are too special. REMEMBER: EACH OF THESE STATEMENTS IS FALSE.

Try substituting numbers such as $2$, $3$, $4$, and $5$.

1. $(x+y)^2=x^2+y^2$

2. $\sqrt{p^2+q^2}=p+q$

3. $3w-2 =\large{\frac { 1 } { 3 w ^ { 2 } }}$

4. $(a^{-1}+b^{-1})^{-1}=a+b$

5. $3·2^x=6^x$

 Note: This stoplight icon will appear periodically throughout the text. Problems with this icon display common errors that can be made. Be sure not to make the same mistakes yourself!