1. For each representation, explain how you find the value of x15 7 x 𝑥 15 x x 7 x 15
Write an equation to match these diagrams.

2. How can we write the equation to represent the diagrams?
How do we solve it algebraically?
2x + 7 = x + 15
x + 7 = 15
Subtract x from both sides
x = 8
Subtract 7 from both sides

3. 6x + 6 = 3x + 12 5x + 6 = 2x + 12 6x + 20 = 3x + 26 5x + 20 = 2x + 26
In your books:
Let’s practice
6x + 6 = 3x + 12
5x + 6 = 2x + 12
6x + 20 = 3x + 26
5x + 20 = 2x + 26
*6x - 6 = 3x + 6
*5x - 6 = 2x + 6
Put a numbers in the boxes so that x = 4
5x + 6 = 3x + 12
5x + 20 = 3x + 26
6x = 3x +
*5x - 6 = 3x + 6
5x = 3x +

4. Each line forms an equation from the two expressions that it joins.
Solve the six equations on your whiteboards, then write the solution to each equation next to each line

5. What do you notice about your answers?

6. Can you make up an expression polygon of your own that has a nice, neat set of solutions?

7. Challenge
How many equations would there be for this expression pentagon?
Can you make 5 expressions for this pentagon that have a nice, neat set of solutions?