Me for number 13,14,15 quickly fast

13. they are not, because the parentese's make it different by applying the order of operations to the two sections, rather than in a long line.

the first one is equal to 1/40     1/4 * 10 = 1/40   
second one is equal to 3/8     10 / 40 / 2 *5 = .25 / 2 * 5 =  3/8

14. g + w = 40  since there are both grape and watermelon in the entire jar of 50

15. algebraic because it involves variables and not just numbers dependent on PEMDAS
 

13. No. If you were to do the exertion with pertness, you would have to:
A) Divide 10 by 40 and get 0.4
B)Divide 0.4 by 5 and get 0.08
C) Multiply 0.08 by 2 and get 0.16

If you were to do PEMDAS for the first one, you would first do the perentasis first:
A) Divide 10 by 40 and get 0.4
B) Multiply 5 by 2 and get 10
C) Divide 0.4 by 10 and get 0.04

These aren't the same.