Question

algebra help?

Answer 1

Hello

Answer 2

This problem is asking us for an equation which can be used to solve for the side length 'd' given that P = the perimeter, and that the remaining three sides are described as 'a, b, and c'

Answer 3

What do you think we should do, given that information?

Answer 4

Well, do you know what the perimeter is?

Answer 5

The perimeter is the length of the exterior of an object. For example:



We have this shape above, with sides x, y, z, and k. Knowing that the perimeter is the length of the exterior of the objects, I know that P is equal to all the sides added up together. Therefore:

\[P = x + y + z + k\]

Answer 6

First tell me what the equation for the perimeter of our irregular polygon would look like.

Answer 7

Correct. And what is the question asking for?

Answer 8

Find d means they want us to solve for d. When you want to solve for a variable, what do you do?

Answer 9

Subtract what?

Answer 10

Hmm, when you want to solve for a variable, what's the first step you do

Answer 11

You want to isolate the variable.

Answer 12

Yeah so how do you get d alone?

Answer 13

Remember our equation is:

\[P = a + b + c + d\]

Answer 14

\[P - d = a + b + c\]

Answer 15

What next

Answer 16

So that isn't the step we were going for. What you want to do, is move the variables a, b, and c, to the other side. As you said, you want to do the opposite operation. They are adding by a, b, and c, so we subtract it.

\[P = a + b + c + d\]
Subtract a from both sides
\[P - a = b + c + d\]
Subtract b from both sides
\[P - a - b = c + d\]
Subtract c from both sides
\[P - a - b - c = d\]

Answer 17

Side d is equal to the perimeter minus the side a, b, and c. That makes sense since if you subtract three of the four sides from the perimeter, you should be left with the length of the remaining side.

Answer 18

Yes

Answer 19

No problem