SOLUTION: 3/18 + 6/17= and -16/40+(-13/20)

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Question 163177: 3/18 + 6/17= and -16/40+(-13/20)
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
When adding and subtracting fractions you need to have the same denominators.
Make the denominators 17*18.
3%2F18+%2B+6%2F17=%283%2F18%29%2817%2F17%29%2B%286%2F17%29%2818%2F18%29
3%2F18+%2B+6%2F17=%283%2A17%29%2F%2817%2A18%29%2B%286%2A18%29%2F%2817%2A18%29
3%2F18+%2B+6%2F17=51%2F%2817%2A18%29%2B108%2F%2817%2A18%29
3%2F18+%2B+6%2F17=159%2F%2817%2A18%29
3%2F18+%2B+6%2F17=%2853%2Across%283%29%29%2F%2817%2A6%2Across%283%29%29
3%2F18+%2B+6%2F17=%2853%29%2F%28102%29
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Make the denominators 40.
-16%2F40%2B%28-13%2F20%29=-16%2F40%2B%28-13%2F20%29%282%2F2%29
-16%2F40%2B%28-13%2F20%29=-16%2F40%2B%28-26%2F40%29
-16%2F40%2B%28-13%2F20%29=-42%2F40
-16%2F40%2B%28-13%2F20%29=-21%2F20