Me with this problem. number 14 btw

Which multiplicative property is being illustrated below? (type commutative, associative, or identity) 5 × 2 × 4 = 2 × 5 × 4

Jake bakes and sell apple pies. he sells each pie for $5.75 . the materials to make the pies cost $40. the boxes jake puts the pies in cost & 12.50 total. how many pies does jake need to sell to earn a profit of $50

Alex measured the length of an item to be 3.7 cm. the actual length is 3.5 cm. what is alex’s percent error?