Translate into algebra: five times the sum of m and n.

1. The word sum tells us to add m and n together first. 2. Parentheses are placed around that sum, m + n, so it is treated as one quantity. 3. The word times then tells us to multiply the whole sum by 5, giving 5 times the quantity m plus n. 4. Writing 5m + n instead would multiply only m by 5 and leave n unmultiplied, which changes the meaning. _Source: OpenStax Elementary Algebra (CC BY 4.0), Ch 1 "Foundations", section 1.2 Use the Language of Algebra_