Answers

Add 72/80 and 42/35

1^st number: 72/80, 2^nd number: 1 7/35

72/80 + 42/35 is 21/10.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 80 and 35 is 560
   
   Next, find the equivalent fraction of both fractional numbers with denominator 560
2. For the 1st fraction, since 80 × 7 = 560,
   72/80 = 72 × 7/80 × 7 = 504/560
3. Likewise, for the 2nd fraction, since 35 × 16 = 560,
   42/35 = 42 × 16/35 × 16 = 672/560
4. Add the two like fractions:
   504/560 + 672/560 = 504 + 672/560 = 1176/560
5. 1176/560 simplified gives 21/10
6. So, 72/80 + 42/35 = 21/10
   In mixed form: 21/10

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