
Example: Find the value of (21)^{2} using formula. Solution: We can write (21)^{2} = (20+1)^{2}. This is the form of (a+b)^{2} = a^{2} + 2ab + b^{2}. = (20)^{2} + 2.20.1 + 1^{2} = 400 + 40 + 1 = 441 Directions: Solve the following problems using the formula and show your work. Also write at least ten examples of your own. 