could someone help me with math?

Question

Area. The length of a rectangle is 4 units more than 9 times the width. Write an expression for the area of the rectangle.

 

9x+4

 

idk what else to do :(

Answer 1

Hello, thank you for taking the time to post your question!

You just want to use the underlying formula for area and then plug in the values that we know. So we have

area = length x width

length = 9 * width + 4

meaning that

area = (9 * width + 4) * width

A = 9w^2 + 4w

So an expression for the Area of the rectangle as a function of the width is A(w) = 9w^2 + 4w

I hope that helps get you moving in the right direction! Feel free to reach out if you have any additional questions beyond that :)

Answer 2

When calculating area for a rectangle you simply multiply the length by the width. In this case, both is given to you. 

 

Your Length (L): = 9x + 4 (as stated above)

 

So your Width (W): = x (since it specifically stated that the length was 4 units more than 9 times the width)

 

Since they want you to write an expression for the area of the rectangle, you can simply multiply your Length by the Width, and the answer would be the expression you are looking for. 

 

 

Area = L * W = x (9x+4), so 9x^2 + 4x should be your answer