Which statement shows the associative property of addition? (u + 7) + 13 = u + (7 + 13) if m + 3 = 18, then 18 = m + 3. 3⋅(5⋅x)=(3⋅5)⋅x 21 + 2y = 2y + 21

Solve with work both bert and ernie received an increase in their weekly salaries. bert's salary increased from $520 to $520. ernie's salary went from $580 to $645. find the percent of increase for each salary. what was the larger of the two percents ?