Question

The length of a photograph is 1 cm less than twice the width. The area is 91cm^2. find the width and length.

Answer 1

Answer:

Width=6.5 cm

Length=12 cm

Step-by-step explanation:

Step 1: Express the lengths and widths

Width=w

Length=l, but 1 cm less than twice the width=(2×w)-1=2 w-1

Step 2: Solve for the length and width

A=L×W

where;

A=area of the photograph

L=length of the photograph

W=width of the photograph

In our case;

A=91 cm²

L=2 w-1

W=w

91=(2 w-1)w

2 w²-w=91

2 w²-w-91=0, is a quadratic equation

solve for w

w={-1±√(-1²-4×2×-91)}/(2×2)

w=(-1±27)/4

w=(27-1)/4=6.5, or (-1-27)/4=-8

Take w=6.5 cm

L=(2×6.5)-1=13-1=12 cm

Width=6.5 cm

Length=12 cm