McGraw Hill Integrated II, 2012
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McGraw Hill Integrated II, 2012 View details
3. Multiplying Polynomials
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Exercise 37 Page 26

a^2-4ab+4b^2

Practice makes perfect
We can find the product of this expression using polynomial identities. In this case, we have the square of a binomial. We will first rewrite the square as the product and then apply the Distributive Property.
(a-2b)^2
(a-2b)(a-2b)
a(a-2b)-2b(a-2b)
a^2-2ab-2b(a-2b)
a^2-2ab-2ab+4b^2
a^2-4ab+4b^2

Alternative Solution

Expanding Negative Perfect Square
We can also simplify the expression by expanding the negative perfect square trinomial.
(a-2b)^2
a^2-2a(2b)+(2b)^2
a^2-2a(2b)+2^2b^2
a^2-2a(2b)+4b^2
a^2-4ab+4b^2