Add 10/45 and 80/21, Solve 10/45 + 3 17/21 as a fraction

Add 10/45 and 80/21

1^st number: 10/45, 2^nd number: 3 17/21

10/45 + 80/21 is 254/63.

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,
10/45 = 10 × 7/45 × 7 = 70/315
Likewise, for the 2nd fraction, since 21 × 15 = 315,
80/21 = 80 × 15/21 × 15 = 1200/315
Add the two like fractions:
70/315 + 1200/315 = 70 + 1200/315 = 1270/315
1270/315 simplified gives 254/63
So, 10/45 + 80/21 = 254/63
In mixed form: 42/63

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