View Full Version : Where do I go from here

hjcruz

07-31-2009, 12:02 PM

Ok here goes my math problem:

The length of a rectangular field is 2 yards more than it's width. Find the width if the area of the field is 120yd(squared).

This is how I have set it up:

x + 2x = 120yd(squared)

Is this correct? I am confused on how I work out a squared yard is that the same way as an quadratic equation?

Any light that could be shed on this would be wonderful thanks in advance?

Janette

Subhotosh Khan

07-31-2009, 12:12 PM

Ok here goes my math problem:

The length of a rectangular field is 2 yards more than it's width. Find the width if the area of the field is 120yd(squared).

This is how I have set it up:

x + 2x = 120yd(squared) <<< That is not area of a rectangle

Area of a rectangle = Length * Width

in this problem

Width = x

Length = 2+x

So

120 = x*(x+2)

Now continue....

Is this correct? I am confused on how I work out a squared yard is that the same way as an quadratic equation?

Any light that could be shed on this would be wonderful thanks in advance?

Janette

hjcruz

07-31-2009, 12:29 PM

ok so then I would work out this problem like this:

x(x+2)=120 yd (squared)

2x+4=120

2x+4-4=120-4

2x = 116

2 2

x= 58

sorry for some reason the 2's don't line up right when I am setting it up to divide but other wise, is this correct. I feel like I must do something about the 120 yd (squared)

Thanks.

Subhotosh Khan

07-31-2009, 12:52 PM

ok so then I would work out this problem like this:

x(x+2)=120 yd (squared)

2x+4=120 <<< That is incorrect.

Before doing this problem - you need to review polynomial multiplication. Please go to:

http://www.purplemath.com/modules/polymult.htm

for a quick review.

For this probelm

[spoiler=:z9lcserf]x(x+2) = 120

x[sup:z9lcserf]2[/sup:z9lcserf] + 2x = 120

(x -10)(x+12) = 0[/spoiler:z9lcserf]

Now what would you do.......

2x+4-4=120-4

2x = 116

2 2

x= 58

sorry for some reason the 2's don't line up right when I am setting it up to divide but other wise, is this correct. I feel like I must do something about the 120 yd (squared)

Thanks.

hjcruz

08-01-2009, 06:13 AM

Ok so I think I may have finally got it. I hope so anyways.

x(x+2) = 120 yd (squared)

x(x) x(2) = 120 yd (squared)

x + 2x = 120

3x = 120

3 3

x=40

Which would make the width of this rectange 40 and the length 40+2 = 42

If this is right is there anything special that I would have to do next or is this it.?

Subhotosh Khan

08-01-2009, 09:59 AM

Ok so I think I may have finally got it.

Like I suggested before - please review polynomial multiplication.

x* x = x[sup:2j0ejint]2[/sup:2j0ejint] ................. like 3*3 = 3[sup:2j0ejint]2[/sup:2j0ejint] = 9 (not 3 as you have claimed)

Click on the reveal button of my answer before.

I hope so anyways.

x(x+2) = 120 yd (squared)

x(x) x(2) = 120 yd (squared)

x[sup:2j0ejint]2[/sup:2j0ejint] + 2x = 120 ....... Incorrect

3x = 120

3 3

x=40

Which would make the width of this rectange 40 and the length 40+2 = 42

If this is right (No) is there anything special that I would have to do next or is this it.?

so you got length = 42 and width = 40 ..... what would be the area of this rectangle (L * W)? Does that match with the given data (120)?

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