Question #00fa2

1 Answer
Oct 8, 2017

the width is 8

Explanation:

Let x be the requested width.

Then the length is #12+x# and the perimeter is #7x#.

There exists the relation:

(the perimeter is the sum of the sides, two times the width and two times the length)

#7x=2(12+x)+2x#

Let's solve the equation:

#7x=24+2x+2x#

#7x-2x-2x=24#

#3x=24#

#x=8#

Then the width is #8# and the length is #12+x=20#