Area using equations

Question

A builder uses parallelogram-shaped stones as decoration around a building's windows. The stones come in many different sizes. Each stone has a base length of x inches and a height of (4x-5) inches. Write a polynomial to describe the area of a stone. Then find the area of a stone that has a length of 6 units.

 

A. 4x²-5; Area= 139 in²

 

B. 4x²-5x; Area= 19 in

 

C. 4x²-5x;Area= 114 in²

 

D. 4x²-5; Area=114 in²

Answer 1

The area of a parallelogram is equal to Base times Height. A = B x H

 

Since the value for B is x, and the value for H is 4x - 5, then

Area = x · (4x - 5)=  4x² - 5x.

 

If x = 6, then (4 · 6² - 5 · 6) =  114

 

The answer is option C