Question

Emily wants to hang a painting in a gallery. The painting and frame must have an area of 31 square feet. The painting is 5 feet wide by 6 feet long. Which quadratic equation can be used to determine the thickness of the frame, x?
Image of a frame 5 feet wide by 6 feet long, with an of x on the bottom and right sides

4x2 + 22x − 1 = 0
4x2 + 22x + 31 = 0
x2 + 11x − 1 = 0
x2 + 11x + 31 = 0

Answer 1

Area=legnth times width=31
the frame must go around the frame with equal legnth, x
so
the total area (meaning the frame +picture) is 5+x by 6+x
31=(5+x)(6+x)
expand
31=30+11x+x^2
minus 31 both sides
0=-1+11x+x^2
x^2+11x-1=0

answer is third one

Answer 2

Answer:   4$x^{2}$ + 22x − 1 = 0

Step-by-step explanation:

Start off with the standard formula to finding area with polynomials and quadratic functions.

(2x + 5)(2x + 6)

Work out like a normal binomial.

4$x^{2}$ + 22x + 30 - 31

(You're subtracting 31 to take out the minimum of what the frame has to be)

4$x^{2}$ + 22x - 1 = 0