Anonymous
Anonymous asked in Science & MathematicsMathematics · 8 years ago

hello, can anyone please teach me or show me how to set up the equations for the word problems? I am stuck on trying how to do them...Thank you

1) a photo is 3 cm longer than it is wide. Find the length and the width if the area is 108 cm^2.

2)a picture frame measures 14 cm by 20 cm, and 160m cm^2 of picture shows. find the width of the frame.

Relevance
• Anonymous
8 years ago

1.Let the width be xcm then

length=x+3cm

area=108cm^2

area=l*b=x(x+3)

=>108=x^2+3x

=>x^2+3x-108=0

So there are 2 values for x,

i.e. (x-9)(x+12)=0

i.e x=9 or x=-12

Since width cannot be -ve

Therefore x=9

i.e Length=12cm and Width=9cm

2.Since the question is not clear I am unable to answer it.

• 1) a photo is 3 cm longer than it is wide. Find the length and the width if the area is 108 cm^2.

Length = L

Width = W

area = length * width = L X W

in this example

L = 3 + W

L X W = 108

now you have two equations with 2 unknowns to solve.

2)a picture frame measures 14 cm by 20 cm, and 160m cm^2 of picture shows. find the width of the frame

i did not get the need exactly but i guess the show area is still proportional to as the fram area

that means

the width will be proportional to length in the range 14 to 20 : W = L * 14/20

W*L = 160

two equations in two unknowns