If both expressions have the same value after substituting and simplifying for x = 6 and x = 10, then they are equivalent. Substitute 6 for each variable, x, in both expressions. Use the order of operations to simplify both expressions. The value of both expressions is 88. Now, substitute 10 for each variable, x, in both expressions. Use the order of operations to simplify both expressions. The value of both expressions is 120. Therefore, the expressions are equivalent.
The new girth is 22 inches; the reference girth is 20 inches. The weight is proportional to the girth, so the reference weight will get multiplied by 22/20 = 11/10.