Expansions — Chapter Summary

Expansion is the process in

Expansion is the process in which the contents of brackets are evaluated. For example, multiplying (a+b)(a+b) and simplifying gives a^2+2ab+b^2.

(a+b)^{2}=a^{2}+2ab+b^{2}

(a+b)^{2}=a^{2}+2ab+b^{2}. It is obtained by expanding (a+b)(a+b) step by step using distribution.

(a

(a-b)^{2}=a^{2}-2ab+b^{2}. It is found by expanding (a-b)(a-b) in the same way.

(a+b)^{2}+(a

(a+b)^{2}+(a-b)^{2}=2(a^{2}+b^{2}). It is obtained by adding Identity I and Identity II.

(a+b)^{2}

(a+b)^{2}-(a-b)^{2}=4ab. It is obtained by subtracting Identity II from Identity I.