# A poster is 25 cm taller than it is wide. It is mounted on of card a piece board that there is a 5 cm border on all sides. If the area of the border alone is 1350 cm what are the dimensions of the poster?

Apr 27, 2018

by my calculations 50 and 75

#### Explanation:

Set up two equations

T = how tall
W = how wide.

T = W + 25 is the first equation

$5 \times \left\{2 \left(T + 10\right)\right\} + 5 \times \left(2 \times W\right) = 1350$

This equation is the total height adding 5 for the top border and 5 for the bottom border. Then multiplying the total height by the width of the border 5, time 2 because there are two sides that are tall Then adding 5 times two widths.

Now substitute the value of W + 25 for T this gives

# 5 xx (2 xx W + 25 +10)+ 5 xx 2W = 1350 solving for W

$5 \times \left(2 W + 50 + 20\right) + 10 W = 1350$

$10 W + 5 \left(70\right) + 10 W = 1350$

$20 W + 350 = 1350$

$20 W + 350 - 350 = 1350 - 350$

$20 W = 1000$

W = 50

T = 50 + 25

T = 75