Answer:
1.) 9
2.) 20
Step-by-step explanation:
1.) 39 is incorrect because they didn't follow the PEMDAS rule.
They subtracted 2 from 15 which is 13, and then they multiplied 13 by 3.
The correct way is to multiply 2 times 3 which is 6, and then subtract 6 from 15 which is 9.
2.) 12 is incorrect because they didn't use PEMDAS.
They added 8 to 16 which is 24, and then divided 24 by 2.
The correct way is to divide 8 by 2 which is 4, and then add for to 16 which 20.