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The width of a rectangular picture is 7 in. Less than the length. The area of the picture is 44 in ^2.

What are the dimensions of the picture?

User Folse
by
5.5k points

1 Answer

1 vote
W = L - 7in

Rectangular area = L × W

44 = (L)×( L - 7)

44 = L × L - 7L

44 = L^2 - 7L

L^2 - 7L - 44 = 0

Applying the Bhaskara

a = 1
b = -7
c = -44

Delta = b^2 -4.a.c

Delta = (-7)^2 - 4.1.(-44)

Delta = 49 + 176

Delta = 225

Then us stay with:

L = [ -b +/- √(Delta) ]/2a

L = [ -(-7) +/- √225 ]/2(1)

L = [ 7 +/- 15 ]/2

We have two possibilities

L' = (7-15)/2

L' = -4

But, L' = -4 it is false.

Because, there isn't mearures negative.

Then,

L'' = [ 7 + 15]/2

L" = 11 in

That's right now.

User Edoardo Pirovano
by
6.0k points