What is the dimension of the rectangle?

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2 Answers
Jan 19, 2018

Length = 10cm
Width = 6cm

Explanation:

Let the width of the rectangle be x cm. Therefore, the length of the rectangle is x+4 cm.

We know that, if we decrease the width by 2cm and the length by 5cm, the perimeter will be 18cm.

That means,

2[(x-2)+(x+4-5)]=18

2[(x-2+x-1)]=18

2(2x-3)=18

2x-3=9

2x=12

x=6

So, the width is 6cm long. Then, the length will be 6+4=10cm long.

Jan 19, 2018

"dimensions are "10" cm by "6" cm

Explanation:

"let the width "=w

"then length "=w+4larrcolor(blue)"4 more than width"

"decrease length by 5 "tow+4-5tow-1

"decrease width by 2 "tow-2

• " perimeter "=(2xx"length")+(2xx"width")

color(white)(xxxxxxxxxx)=2(w-1)+2(w-2)

color(white)(xxxxxxxxxx)=2w-2+2w-4

color(white)(xxxxxxxxxx)=4w-6

"now perimeter "=18

rArr4w-6=18

"add 6 to both sides"

4wcancel(-6)cancel(+6)=18+6

rArr4w=24

"divide both sides by 4"

(cancel(4) w)/cancel(4)=24/4

rArrw=6

rArr"width "=6" cm "

rArr"length "=w+4=6+4=10" cm"