Solve the system by substitution.
5x + 9y = 21
-6y = x

The base of a triangle exceeds the height by 9 inches. if the area is 180 square inches, find the length of the base and the height of the triangle.

Use the ratio test to determine whether ∑n=14∞n+2n! converges or diverges. (a) find the ratio of successive terms. write your answer as a fully simplified fraction. for n≥14, limn→∞∣∣∣an+1an∣∣∣=limn→∞.

In the next 10 month,colin wants to save $900 for his vacation.he plans to save $75 each of the first 8 months. how much must he save each of the last 2 months in order to meet his goal if he saves the same amount each month ?