Answer:
Step-by-step explanation:
twice a number .....multiplication
decreased by 4.....subtraction
divided by 8.....division
addition is missing <====
although, twice a number could also be addition.....but I have never used it for addition
lets say ur number is 4.......twice the number 4 could be : 2 * 4 or 4 + 4
Answer:
Step-by-step explanation:

Answer: a
Step-by-step explanation:
did the test
Answer:
115
Step-by-step explanation:
4*2+8(2) = 24
31
7(2)+30 = 44
3*2-5(2)+20 = 6-10+20 = -4+20 = 16
24+31+44+16
115