Complete the equation to show two equivalent expressions.

g2 – 4g – 21 = (g – )(g + )

G^2 - 4g - 21 = (g-7)(g+3)

Step 1: Create an X Puzzle
In order to do this, create a big x on a piece of paper. Then place the -21 on the top space and place the -4 from the 4g on the bottom space. Next, you have to figure out what two numbers multiply to equal -21, and what two numbers add up to equal -4. Those two numbers are the numbers that you put in the side spaces. You should end up getting -7 and +3.

Step 2: Those two numbers can now be used to complete your equation. 

I hope this helps you. I know my explanation in Step 1 was probably confusing!

They are somewhat similar

There are 48 blue cards total