### Home > CC4 > Chapter 8 > Lesson 8.1.5 > Problem 8-73

If two expressions are

**equivalent**, they can form an equation that is considered to be**always true**. For example, since 3(*x*− 5) is equivalent to 3*x*− 15, then the equation 3(*x*− 5) = 3*x*− 15 is always true for any value of*x*. Homework Help ✎If two expressions are equal only for certain values of the variable, they can form an equation that is considered to be

**sometimes true**. For example,*x*+ 2 is equal to 3*x*− 8 only when*x*= 5, so the equation*x*+ 2 = 3*x*− 8 is said to be sometimes true.If two expressions are not equal for any value of the variable, they can form an equation that is considered to be

**never true**. For example,*x*− 5 is not equal to*x*+ 1 for*any*value of*x*, so the equation*x*− 5 =*x*+ 1 is said to be never true.Is the equation (

*x*+ 3)^{2}=*x*^{2}+ 9 always, sometimes, or never true? Justify your reasoning completely.

The equation is sometimes true.

It is only true when *x* = 0.