the length of a rectangle is 3cm longer than its width.The area is 30cm2.Find its width.

Question

answer must be given correct to 1 decimal place.There is no perimeter given.

Answer 1

Let a the length, And b the width, Then: a=b+3 b=a-3 A=a*b=a(a-3)=a²-3a (cm²) But a²-3a=30 (cm²) a²-3a-30=0 D=(-3)² -4*(-30)=129, a=½[3±|√129] a=½[3+√129]

Answer 2

let

    length="l"

    width="w"

if..length=l,then w=l+3  (from the relation given)

Area=l*(l+3)

30=l^2+3l

l^2+3l-30=0

from the general quadratic formula

l=[-3+(3^2+120)^1/2]/2

l=[-3+(129)^1/2]/2

l=4.175cm

 

 

 

 

 

 

 

 

 

 

 

 

Answer 3

D. Exec