Simplify the following:
1/3 - 1/6 + 4/18
The gcd of 4 and 18 is 2, so 4/18 = (2×2)/(2×9) = 2/2×2/9 = 2/9:
1/3 - 1/6 + 2/9
Put 1/3 - 1/6 + 2/9 over the common denominator 18. 1/3 - 1/6 + 2/9 = 6/18 - 3/18 + (2×2)/18:
6/18 - 3/18 + (2×2)/18
2×2 = 4:
6/18 - 3/18 + 4/18
6/18 - 3/18 + 4/18 = (6 - 3 + 4)/18:
(6 - 3 + 4)/18
6 + 4 = 10:
(10 - 3)/18
10 - 3 = 7:
Answer: 7/18