Answer to 25:
It's basically simple algebra where you move the numbers to find that one unknown variable.
Perimeter is the outer length of a shape. It's the distance around its edge. Finding the perimeter just means adding up the lengths of all it's sides.
However we aren't finding the perimeter, we're rearranging the equation to find its length and width.
So they've made it easier for you by giving you the equation itself.
[ Width = x
Length = 2x (Because they mentioned that the length is two times the width). ]
Equation: Perimeter = x + x + 2x + 2x
So input the info you have and rearrange the equation by using simple algebra rules:
36 = x + x + 2x + 2x
36 = 2x + 4x
36 = 6x
36/6 = x
x = 6
You've discovered the width. But how about the length? Simple:
= 2(x)
= 2(6)
= 12
So:
Width = 6
Length = 12
Answer to 26:
Just rearrange it.
4(n+3) = 32
n+3 = 32/4
n+3 = 8
n = 8-3
n = 5
Answer to 27:
Okay so this is a bit confusing to me since it says "same selling price". Meaning in the end, the person doesn't make any profit? Because she uses the same selling price.
So it doesn't make sense. Thus I assume by the phrase "same selling price" is the new selling price after the percentage added:
First find the cost of ONE shirt
$600/40 = $15
Then add the percentage given
600 × 40/100 = 240
= $600 + 240
= $840
Then divide it by the amount of shirts bought to find the new price of ONE shirt
= $840/40
= $21
So now to find the profit she makes per shirt by subtracting the original price of one shirt
= $21 - $15
= $6
