Add 21/70 and 72/80, Solve 21/70 + 72/80 as a fraction

Add 21/70 and 72/80

21/70 + 72/80 is 6/5.

Find the least common denominator or LCM of the two denominators:
LCM of 70 and 80 is 560

Next, find the equivalent fraction of both fractional numbers with denominator 560
For the 1st fraction, since 70 × 8 = 560,
21/70 = 21 × 8/70 × 8 = 168/560
Likewise, for the 2nd fraction, since 80 × 7 = 560,
72/80 = 72 × 7/80 × 7 = 504/560
Add the two like fractions:
168/560 + 504/560 = 168 + 504/560 = 672/560
672/560 simplified gives 6/5
So, 21/70 + 72/80 = 6/5
In mixed form: 11/5

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