David wants to hang a mirror in his room but the mirror and frame must not have an area larger than 8 square feet. The mirror is 2 feet wide and 3 feet long. Which quadratic equation represents the area of the mirror and frame combined? (The frame must have equal width of x on each side.)

2x2 + 14x − 2 = 0

3x2 + 10x − 8 = 0

4x2 + 10x − 2 = 0

x2 + 7x − 8 = 0

Question

David wants to hang a mirror in his room but the mirror and frame must not have an area larger than 8 square feet. The mirror is 2 feet wide and 3 feet long. Which quadratic equation represents the area of the mirror and frame combined? (The frame must have equal width of x on each side.)



 2x2 + 14x − 2 = 0

 3x2 + 10x − 8 = 0

 4x2 + 10x − 2 = 0

 x2 + 7x − 8 = 0

anonymous · Answer

attachment

anonymous · Answer

The Area is length times height right? (-: Now you just have to see what the length and height is in this graph you have posted.

anonymous · Answer

thats it? but whats with those equations?

anonymous · Answer

well it will lead to a quadratic equation

$$A = lh =8 $$ now you have to substitute l and h into the equation, what would you guess is the length when you look at the graph?

anonymous · Answer

3ft

anonymous · Answer

no the entire length of the graph, you want to include the mirror and the frame

anonymous · Answer

the entire area shouldn't be bigger than 8 after all.

anonymous · Answer

oh..5ft.

anonymous · Answer

no the length is 2x+2

anonymous · Answer

ugh. okay so the length is 2xc+2 and the width would be 3x+2?? or is that wrong too?

anonymous · Answer

the width would be 2x+3 if you meant that.

anonymous · Answer

oops yea

anonymous · Answer

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