Question

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?

Answer 1

by my calculations 50 and 75

Explanation:

Set up two equations

T = how tall
W = how wide.

T = W + 25 is the first equation

`5xx{2 ( T + 10) } + 5 xx ( 2 xx W) = 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 xx ( 2W + 50 +20) + 10 W = 1350`

`10W + 5 ( 70 ) + 10W = 1350`

`20 W + 350 = 1350`

`20W + 350 - 350 = 1350 - 350`

`20 W = 1000`

W = 50

T = 50 + 25

T = 75