Question 548969: a picture frame measures 24cm by 15 cm.There is 220 cm squared of picture showing.The frame is of uniform thickness.Find the thickness. Answer by mananth(16946) (Show Source):
You can put this solution on YOUR website! Area of picture frame =24*15 = 360 m^2
let the uniform width be x on length & width on each side
width of picture = 15-2x
length of picture = 24-2x
(15-2x)(24-2x)=220
360-30x-48x+4x^2=220
360-220-78x+4x^2=0
4x^2-78x+140=0
/2
2(2x^2-39x+70)=0
2(2x^2-35x-4x+70)=0
2(2x(x-17.5)-2(2x-35))=0
2((x-17.5)(x-2))=0
Neglect 17.5 since it is greater than width
so width = 2feet
m.ananth@hotmail.ca
