Answer:
$30.72
Step-by-step explanation:
You were right with your answer, the teacher is probably just wanting you to tip on the subtotal (before tax) instead of the total total. Instead of doing total+tax+tip, we're going to figure out the tax and tip separately and then add it all together.
<u>Tipping on the subtotal (what your teacher wanted)</u>
20% of $24 = $4.80
8% of $24 = $1.92
$24+$4.80+$1.92=$30.72
<u>Tipping on the total (what you did)</u>
8% of $24 is $1.92
New total is $25.92
20% of $25.92 is $5.18
$25.92 + $5.18 = $31.10
Before we do any solving, we need to simplify both sides.
On the left, we can simplify -2x + 3x - 5 to x - 5.
On the right, we can simplify 6 - 21 to -16.
So we have x - 5 = -16.
Solving from here, we add 5 to both sides to get x = -11.
The first two pieces are the same, let each of those equal x, so you have x + x = 2x
The 3rd piece is the sum of the first two + 4, so this would be 2x + 4
Now you have 2x + 2x + 4 = 100 cm
Combine like terms:
4x +4 = 100
Subtract 4 from both sides
4x = 96
Divide both sides by 4
X = 24
First piece is 24 cm
Second piece is 24 cm
Third piece is 52 cm