Hi Zach!
-14/15+7/8
In order to add fractions, the denominators (bottom numbers) must be the same (common denominators). So we have to rewrite the problem using equivalent fractions with the same denominators. Remember, anytime you have a fraction with the same numerator and denominator, it equals 1. So if I multiply something times 8/8, it's just like multiplying times 1! However, this gives us common denominators. I multiply the top and bottom of the 1st fraction by the denominator of the 2nd fraction (8) and multiply the top and bottom of the 2nd fraction by the denominator of the 1st fraction (15).
- 14 × 8 = -112
15 × 8 120
7 × 15 = 105
+8 × 15 120
Now restate your problem with your new fractions and solve:
-112/120+105/120= -7/120
