Problem Solving Function!

[blondezilla724]

Express perimeter, P, of a rectangle as a function of the length x and width, which is twice the length...

I know i need to know the Perimeter formula, which is 2(l*w) and know that the length=x and width=2x, but I don't know how to set up the problem.

I tried and got an answer of P(x)= 2(x+2x)

 

[Mrspi]

Express perimeter, P, of a rectangle as a function of the length x and width, which is twice the length...

I know i need to know the Perimeter formula, which is 2(l*w) and know that the length=x and width=2x, but I don't know how to set up the problem.

I tried and got an answer of P(x)= 2(x+2x)

You may want to review the formula for the perimeter of a rectangle.

In general, the perimeter of a polygon is the sum of the lengths of its sides.

So...for a rectangle,

permeter = length + width + length + width
permeter = 2*length + 2*width

Now...see what happens with the given length and width.

 

[Denis]

I tried and got an answer of P(x)= 2(x+2x)

That's correct; simplify to 2(3x), then 6x

Btw, your 2(l * w) should be 2(l + w)

 

[blondezilla724]

isnt 2(l+w) the same thing as 2*l + 2*w?
like if you said 2(1+3) wouldnt it be the same as saying (2*1) + (2*3) ?

 

[mmm4444bot]

isnt 2(l+w) the same thing as 2*l + 2*w? Both expressions have the same value.

2(l + w) = 2l + 2w

Have you seen the Distributive Property ?

A(B + C) = A*B + A*C

It's famous.

like if you said 2(1+3) wouldnt it be the same as saying (2*1) + (2*3) ?

If you apply the Distributive Property to the expression

2(1 + 3)

you will get the expression 2(1) + 2(3)

I don't know what motivated your two questions above.

Simplification by first applying the Distributive Property:

2(x + 2x)

2x + 2(2x)

2x + 4x

6x

Simplification by first following the Order of Operations:

2(x + 2x)

2(3x)

6x

Both approaches are valid.