Answers

Add 42/70 and 90/72

1^st number: 42/70, 2^nd number: 1 18/72

42/70 + 90/72 is 37/20.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 70 and 72 is 2520
   
   Next, find the equivalent fraction of both fractional numbers with denominator 2520
2. For the 1st fraction, since 70 × 36 = 2520,
   42/70 = 42 × 36/70 × 36 = 1512/2520
3. Likewise, for the 2nd fraction, since 72 × 35 = 2520,
   90/72 = 90 × 35/72 × 35 = 3150/2520
4. Add the two like fractions:
   1512/2520 + 3150/2520 = 1512 + 3150/2520 = 4662/2520
5. 4662/2520 simplified gives 37/20
6. So, 42/70 + 90/72 = 37/20
   In mixed form: 117/20

MathStep (Works offline)

Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad

Related: ⁸⁴/₇₀+⁹⁰/₇₂

Add Fractions Calculator