Answers

Subtract 30/18 from 42/45

1^st number: 42/45, 2^nd number: 1 12/18

42/45 - 30/18 is -11/15.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 45 and 18 is 90
   
   Next, find the equivalent fraction of both fractional numbers with denominator 90
2. For the 1st fraction, since 45 × 2 = 90,
   42/45 = 42 × 2/45 × 2 = 84/90
3. Likewise, for the 2nd fraction, since 18 × 5 = 90,
   30/18 = 30 × 5/18 × 5 = 150/90
4. Subtract the two like fractions:
   84/90 - 150/90 = 84 - 150/90 = -66/90
5. After reducing the fraction, the answer is -11/15

MathStep (Works offline)

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

Related: ⁸⁴/₄₅-³⁰/₁₈ ⁴²/₄₅-⁶⁰/₁₈ ⁴²/₉₀-³⁰/₁₈ ⁴²/₄₅-³⁰/₃₆ ⁴²/₄₅-⁹⁰/₁₈ ⁴²/₄₅-³⁰/₅₄ ⁴²/₄₅-³⁰/₉₀

Subtract Fractions Calculator