Anna's back Garden consists of a rectangular lawn measuring 9m by 7m, surrounded by a gravel path of width X metres. Find, and simplify, an expression for the total area of the garden.​

Annas back Garden consists of a rectangular lawn measuring 9m by 7m surrounded by a gravel path of width X metres Find and simplify an expression for the total class=

Respuesta :

A rectangular lawn measuring 8m by 4m is surrounded by a flower bed of uniform width.

The combined area of the lawn and the flower bed is 165m^2. What is the width of the flower

:

Let x = the width of flower bed

:

Then the overall dimensions (flower bed & lawn) will be:

(2x + 8) by (2x + 4)

:

Overall area

(2x+8)*(2x+4) = 165

FOIL

4x^2 + 8x + 16x + 32 = 165

A quadratic equation

 

4x^2 + 24x + 32 - 165 = 0

4x^2 + 24x - 132 = 0

Simplify, divide by 4, results:

x^2 + 6x - 33 = 0

Use the quadratic formula to solve this