How do i solve this by using substitution ? y=3x-24 5x-y=28 solving for x and y.

Karianne and lucius are analyzing a linear function on a graph. karianne says that unit rate is equal to rate of change, but that slope is calculated differently. lucius says that unit rate, rate of change, and slope are calculated the same way. who is correct? explain your answer.

When you answer this can you explain

45% of the trees in a park are apple trees. there are 27 apple trees in the park. how many trees are in the park in all?