Answer:
A.2/3
Step-by-step explanation:
Find the least common denominator or LCM of the two denominators:
LCM of 21 and 7 is 21
Next, find the equivalent fraction of both fractional numbers with denominator 21
For the 1st fraction, since 21 × 1 = 21,
5
21
=
5 × 1
21 × 1
=
5
21
Likewise, for the 2nd fraction, since 7 × 3 = 21,
3
7
=
3 × 3
7 × 3
=
9
21
Add the two like fractions:
5
21
+
9
21
=
5 + 9
21
=
14
21
14/21 simplified gives
2
3
So, 5/21 + 3/7 = 2/3
