Hello, ^_^Engineer_Adam^_^!

The printed area of a rectangular poster is 704 in².

The printed area plus the area of the margins is 1200 in².

Find the dimension of the poster if each of the margins is 4" wide. Code:

: 4 : - x - : 4 :
- * - - - - - - - - * -
4 | | :
- | * - - - - * | :
: | | | | :
: | | | | :
y | |y | | y+8
: | | | | :
: | | x | | :
- | * - - - - * | :
4 | | :
- * - - - - - - - - * -
: - - - x+8 - - - :

The length of the printed area is *x.*

The height of the printed area is *y.*

. . Then: .xy = 704 . → . y = 704/x **[1]**

The length of the poster is *x + 8.*

The height of the poster is *y + 8.*

. . Then: .(x + 8)(y + 8) = 1200 **[2]**

Substitute [1] into [2]: .(x + 8)(704/x + 8) .= .1200

. . which simplifies to: .8x² - 432x + 5632 .= .0

. . Divide by 8: . x² - 54x + 704 .= .0

. . which factors: .(x - 22)(x - 32) .= .0

. . and has roots: .x .= .22, 32 . → . y .= .32, 22

Hence, the dimensions of the printed area is: 22 x 32 inches.

Therefore, the dimension of the poster is: **30 x 40 inches**.