Which problem demonstrates the associative property? 5.2 (3.1 + 1.9) = (5.2 • 3.1) + (5.2 • 1.9)

5.2 + 1.9 + 3.1 = 10.2

(5.2 + 3.1) + 1.9 = 5.2 + (3.1 + 1.9)

None of the above

Need fast answers!,!!!

On monday,mrs.wise bought 3 lbs of apples at $4per lb= 4*3=$12on tuesday ,20%off and she buy 5 lbs of apples = $4-20%=3.20*5lb=$16example: other wise when she buy 5lbs on monday she have to spend 4*5=20

What’s your question.

Ithink it's the first one ( let me know if it right)