show that x satisfies the equation x2 - 18x + 32 = 0

  • 0 votes

there is a garden in the shape of a rectangle measuring 10m by 8m.
there is an area covered by grass
the area covered by the grass is  3/5 of the area of the garden.
show that x satisfies the equation x2 - 18x + 32 = 0

Posted Sat 4th June, 2011 @ 21:34 by sabba

2 Answers

  • 0 votes

is x supposed to be the area of the garden covered or something like that?
If you just factorise, you should get (x-2)(x-16). Is that what you're looking for? :)

Answered Sat 4th June, 2011 @ 21:50 by Kelly:)
  • -1 votes

if i remember from last year x is the width of the path right?

1.  find the area of the grass

    so 8x10=80

80/5 x 3 = 48

2. then write an equation for the area using x

(10-x)(8-x)=48

3. expand the brackets

80-8x-10x+x^2=48

4. simplify and rearrange

x^2 -18x+80=48

80-48=32

so x^2-18x+32=0

in an exam if the question gives you the answer and the next part is using it but you can't get the first bit. don't worry, use the equation your given so you don't loose those marks

pui pui

Answered Sun 5th June, 2011 @ 10:59 by Pui Pui
Edited by Pui Pui on Sun 5th June, 2011 @ 11:00