7-8. If two expressions are equivalent, they can form an equation that is considered to be always true. For example, since 31x 5) is equivalent to 3x -15, then the equation 3(x - 5) = 3x - 15 is always true, that is, true for any value of x.
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 3x - 8 only when x = 5, so the equation x + 2 = 3x - 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 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 = x² + 9 always, sometimes or never true? Justify your reasoning completely.