212k views
0 votes
Sarah wants to hang a mirror in her room. The mirror and frame must have an area of 15 square feet. The mirror is 3 feet wide and 4 feet long. Which quadratic equation can be used to determine the thickness of the frame, x?

Sarah wants to hang a mirror in her room. The mirror and frame must have an area of-example-1
User Micheline
by
8.3k points

2 Answers

3 votes
4-y×3-v=x is an equation.
Hope it helps!

User Wvanbergen
by
8.1k points
5 votes

Answer:


4x^2+14x-3=0

Explanation:

We have been given that the mirror is 3 feet wide and the thickness of the frame is x, so width of the frame would be
x+x=2x.

The width of mirror with frame would be
2x+3.

Similarly, the length of the frame would be
x+x=2x and the length of mirror with frame would be
2x+4.

We know that area of rectangle is width times length, so area of frame with mirror would be
(2x+3)(2x+4).

We are told that The mirror and frame must have an area of 15 square feet, so we can equate our equation with 15 as:


(2x+3)(2x+4)=15

Upon simplifying our equation, we will get:


4x^2+8x+6x+12=15


4x^2+14x+12=15


4x^2+14x+12-15=15-15


4x^2+14x-3=0

Therefore, our required equation would be
4x^2+14x-3=0.

User Vishal G
by
8.5k points