Question

A rectangular looking glass 18cm by 12cm has a wooden frame of uniform width .If the area of the frame is equal to that ofbthe looking glass, find the dimensions of the framed glass.
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Answer 1

Step-by-step explanation:

let x= width of frame

width of frame with picture=15+2x

length of frame with picture=18+2x

Area of frame with picture=(18+2x)(15+2x)=(270+66x+4x^2)

Area of picture alone=18*15=270

Area of frame with picture-Area of picture alone=234

270+66x+4x^2-270=234

4x^2+66x-234=0

2x^2+33-117=0

(x-3)(2x+39)

x=3 cm

or

x=-39/2=-19.5(reject, x>0)

ans:

Width of frame= 3 cm with outside dimensions 21 by 24 cm