Does anyone know how to do algebra/geometry? I cant figure out my homework =[?

Question

The length of a rectangle is 3 cm more than the width. The area is 70 cm[squared]. Find the dimensions of the rectangle.

Thats the problem. Im sure its simple but I dont know where to start. Can anyone please explain how to do it? It would be VERY much appreciated.

Answer 1

This is algebra in disguise.

We know to get the area, that's just length times width, right?

70cm squared = (length +3 ) * width

You should be able to take it from here.

Answer 2

1) First, draw a rectangle (it really helps if you look at it visually too).

2) Label what you know on that rectangle. You know that the length is 3cm more than the width..so basically you don't know the value of the width at all so let's say, for instance, that width = x. Therefore,the length would be x+3 because it's three more than the width which we are going to represent as x.

3) Now you have variables you can work with and you know that Area = 70cm^2. You also know that Area = L x W, so rewrite it with the variables you have now (it should look something like this: A = (x)(x+3) = 70cm^2).

4) Solve that equation: A= (x)(x+3) = 70cm^2.

- Distribute.
(x)(x+3) = 70 becomes x^2+3x = 70

- Put everything on one side so that the equation equals 0.
x^2+3x-70 = 0

- Factor it out.
(x+10)(x-7) = 0

- Solve for x now (Don't let this part confuse you yet since you will have two answers for x!).
x+10 = 0
x = -10

x-7 = 0
x = 7

5) You have two answers for x but you know that -10, since it's a negative number, is not a valid dimension for anything. So x = 7.

6) Now that you have solved for x, plug that number into the variables you had for length and width, x (as width) and x+3 (as length).

7) The width is 7 and the length is 10 since x = 7, width solved, and 7+3 = 10, length solved. Done!

Answer 3

*First we should extract Data from the question:

-We have a Rectangular
-Length is 3 cm more than Width
-Area is 70 cm
-Find the Length (L) and Width (W)

====================================

*Answer:

We say Width (W) = y ... this will lead Length (L) = y+3

Rectagular Area = Width * Length

So => Area = W * L
70 = y * (y+3)
70 = y^2 + 3y

To make things fast just try some numbers for this equation to see do you get the value 70?

y=5 => 5^2 + 3*2 = 25 + 6 = 31 ...
Less than 70 choose a bigger number

y=10 => 10^2 + 3*10 = 100 + 30 = 130 ...
Bigger than 70 choose something less between 5 and 10

y=7 => 7^2 + 3*7 = 49 + 21 = 70 Yurika !!!

Width = 7 cm
Lenght = 7+3 = 10 cm

Problem solved :)

Answer 4

Let
l = length
and
w = width
of the rectangle. Then
70 = A = l * w,
where A is the area of the rectangle. From the information, the length is 3 more than the width, so
l = w + 3. Thus
70 = ( w +3 ) * ( w ) = w^2 + 3w.
Set one side equal to zero and solve the quadratic equation
w^2 + 3w - 70 = 0 -> ( w + 10 ) * ( w - 7 ) = 0 -> w = -10 or w = 7
Since length and width are always positive
w = 7 and l = w + 3 = 10

Answer 5

you are able to continually use a calculator and attempt dividing the numbers. despite if, there are some undemanding rules to determine maximum numbers. those rules are strategies workouts (sturdy for the strategies and the ego) yet at the instant are not inevitably undemanding to undergo in strategies all. working example: all even numbers are divisible by 2, all numbers that bring about 5 or 0 are divisible by 5; all numbers ending in 0 are divisible by 10; if the sum of the digits in a variety is comparable to 3, 6, or 9 the variety is divisible by 3: and so on. attempt it and study approximately those rules or info approximately numbers.

Answer 6

I did it by trial and error

The dimensions are 7 and 10

I kept plugging numbers into the equation w^2 + 3w = 70

For some reason I couldn't figure out how to do it any other way.

Answer 7

2(x+3) +2x =70
2x +6 + 2x =70
4x +6 =70
4x -6
4x = 64
x= 16

L=16 + 3= 19cm
w=16cm

Answer 8

how can it be squared while the width and length don't equal.

Answer 9

x*(x+3)=70

solve for x
x would be your width
and x + 3 would be your length