247,750 views
24 votes
24 votes
The area of a rectangular room is 750 square feet. The width of the room is 5 feet less than the length of the room. Which equations can be used to solve for y, the length of the room? Select three options. y(y + 5) = 750 y2 – 5y = 750 750 – y(y – 5) = 0 y(y – 5) + 750 = 0 (y + 25)(y – 30) = 0

User Adocad
by
3.1k points

1 Answer

16 votes
16 votes
With the given information, we can know that the area is 750 square feet.

The length we can set as y, meaning the width would be (y-5).

So, from these equations, which are the correct ones?

1. y(y+5) = 750
This not correct, as it should be a minus sign instead of addition.

2. y^2-5y = 750
This is correct, because when we do the normal area calculation, y^2-5y is what you would get if you do y(y-5).

3. 750 - y(y-5) = 0
This is correct, the total area minus the calculation of the total area would be 0.

4. y(y-5) + 750 = 0
This is not correct, because this is an area calculation it's impossible to get a negative. So it would not work.

5. (y+25)(y-30) = 0
This is correct. Once you simplify it, it becomes y^2 - 5y - 750 = 0. And then we can move the -750 over so it becomes a positive.


Hope this helped! <3
User Tom Bird
by
2.6k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.