Find the sum and express it in simplest form
(7n^3-9n)+(-8n^3+6n-3)

2x minus y equals 6, x plus y equals negative 3

Mis the midpoint of rq if rm equals 2x + 5 and mq equals 4x - 9 what is the length of rq

Upstream: 1.04 = x – y downstream: 2.08 = x + y aro can paddle at a speed of miles per hour. the river’s speed is miles per hour.