Answer:When adding and subtracting fractions, the denominators (the bottom numbers) must be the same. To do this, we need to find a common denominator. In this case, the least common multiple of the denominators 50 and 10 is 50. To convert 7/10 to an equivalent fraction with a denominator of 50, we multiply both the numerator and denominator by 5:
7/10 x 5/5 = 35/50
Now we can add the two fractions together:
3/50 + 35/50 = 38/50
So, the answer is 38/50.
Explanation: