3. Multiplying Polynomials
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Use the FOIL Method.
Consider the last example in the table in Part A.
Use the FOIL Method.
Table:
| Expression | (Expression)^2 |
|---|---|
| x+5 | x^2+10x+25 |
| 3y+1 | 9y^2+6y+1 |
| z+q | z^2+2zq+q^2 |
See solution.
a^2+2ab+b^2
To complete the table, we need to use a* a=a^2, and the FOIL Method.
| Expression | (Expression)(Expression) | FOIL Method | (Expression)^2 |
|---|---|---|---|
| x+5 | (x+5)(x+5) | (x)(x)+(x)(5)+(5)(x)+(5)(5) | x^2+10x+25 |
| 3y+1 | (3y+1)(3y+1) | (3y)(3y)+(3y)(1)+(1)(3y)+(1)(1) | 9y^2+6y+1 |
| z+q | (z+q)(z+q) | (z)(z)+(z)(q)+(q)(z)+(q)(q) | z^2+2zq+q^2 |
Let's remove the intermediate steps.
| Expression | (Expression)^2 |
|---|---|
| x+5 | x^2+10x+25 |
| 3y+1 | 9y^2+6y+1 |
| z+q | z^2+2zq+q^2 |
Consider the example below.
Let's find an equivalent expression for the square of the sum a+b.
This expression represents the square of sum of a and b. (a+b)^2=a^2+2ab+b^2