Question

. The Length of a rectangle exceeds the breadth by 5m. If the length was decreased by 4m and the
breadth was doubled. Then the area would be increased by 40m^2
. Find the length.

Answer 1

Answer:

13m

Step-by-step explanation:

Let breadth be x

Since length exceeds breadth by 5m,

length=x+5

Thus, area of rectangle=l*b=x(x+5)=x²+5x m²

After changes in measurements,

length=x+5-4=x+1

breadth=2x

Area=l*b=2x(x+1) cm²=2x²+2x

Since area is reduced by 40m²,

New area-old area=40

2x²+2x-(x²+5x)=40

2x²-x²+2x-5x=40

x²-3x-40=0

x²-8x+5x-40=0

x(x-8)+5(x-8)=0

x= -5. or. x=8

since length can't be-ve,

x=8

length=x+5=13m