Question 553078
(2x + 7) + 5x



2x + (7 + 5x) ... Associative property of addition



2x + (5x + 7) ... Commutative property of addition



(2x + 5x) + 7 ... Associative property of addition



7x + 7



So (2x + 7) + 5x simplifies to 7x + 7