<PRE><B>Question 1145528</B>
A photograph is enlarged to 20cm by 30cm and framed.
 The frame is to include a border around the photograph equal in area to the photograph.
 Find the width of the border.
:
Find the area of the photo: 20 * 30 = 600 sq/cm, border is also 600 so the 
overall area = 1200 sq/cm
let x = the width of the border therefore:
 overall dimensions is (2x+20) by (2x+30)
Area equation
(2x+20)*(2x+30) = 1200
FOIL
4x^2 + 60x + 40x + 600 = 1200
4x^2 + 100x + 600 - 1200 = 0
4x^2 + 100x - 600 = 0
simplify, divide by 4
x^2 + 25x - 150 = 0
You can use the quadratic formula, a=1; b=25; c=-150; but this will factor to:
(x+25)(x-5) = 0
Positive solution
x = 5 cm is the width of the border
:
:
Check this out
(2(5)+20) * (2(5) + 30) =
30 * 40 = 1200</PRE>