Answer: 7 π r² + π r³
Step-by-step explanation:
1) The general formula for the volumen, V, of a cylinder with radius r and height h is:
V = π r² h
2) Now you have the condition that the height is 7 inches greater than the radius, that is:
h = 7 + r
3) Replace h with its expression
V = π r² (7 + r)
4) Expand the product (use distributive property):
V = π (7r²) + π r³ = 7 π r² + π r³
Answer: 7 π r² + π r³