Explanation:
remember the priorities :
1. brackets
2. exponents
3. multiplications and divisions
4. additions and subtractions
inside every category you go usually from left to right, but you can use the commutative property where applicable.
4 + 5 - 3 = 4 + 5 - 3 = 4 + 5 - 3 = 4 - 3 + 5 = 6
8×3 - 5 = 24 - 5 = 19
15/3 + 10 = 5 + 10 = 15
8 + 3 - 1×2 = 8 + 3 - 2 = 9
14×3 - 2 = 42 - 2 = 40
(3 + 5)×2 = 8×2 = 16
10 + 7 + 2×1 = 10 + 7 + 2 = 19
16/8 + 4 = 2 + 4 = 6
7 + 5/5 = 7 + 1 = 8
20/4×6 = 5×6 = 30