Jeanette,

You are asked to add two fractions and to do so the fractions need to have the same denominator, called a common denominator. The denominators you have are $50$ and $60.$ A common denominator is number which is a multiple of both $50$ and $60.$ $50 = 5 \times 10$ and $60 = 6 \times 10$ so $5 \times 6 \times 10 = 300$ is a multiple of both. To express the two fractions with the same denominator of $300$ multiply the numerator and denominator of the first fraction by $6$ and the numerator and denominator of the second fraction by $5.$ This gives

\[\frac{12.75^2}{50} + \frac{13.49^2}{60} = \frac{6 \times 12.75^2}{6 \times 50} + \frac{5 \times 13.49^2}{5 \times 60}.\]

Can you complete the problem now?

Write back if you need more help,
Harley