Answer: top question : 36 middle question: 21 bottom question: 18
Explanation:
top question:
(10+8)(4)/ (6/3)
parentheses first
(18)(4)/ (2)
multiply 18 by 4
72/2
divide
36
middle question:
3+2(1+8)
parentheses first
3+2(9)
multiply 2 by 9
3+18
add
21
bottom question:
3(13-(1+6))
inner parentheses first
3(13-7)
subtract inside parentheses
3(6)
multiply
18