Compare 42/45 and 12/21
42/45 is greater than 12/21
Steps for comparing fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 21 is 315
Next, find the equivalent fraction of both fractional numbers with denominator 315 - For the 1st fraction, since 45 × 7 = 315,
42/45 = 42 × 7/45 × 7 = 294/315 - Likewise, for the 2nd fraction, since 21 × 15 = 315,
12/21 = 12 × 15/21 × 15 = 180/315 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 294/315 > 180/315 or 42/45 > 12/21
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