Question

find the product of the following using the identity (a+b)(a-b)=a^2-b^2
i](a+3)(a-3)
ii](5xy-7)(5xy+7)
iii]105×95


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Answer 1

Answer:

1. a^2-3^2=a^2-9.
2. 5xy^2-7^2=5xy^2-49
3. 75

Step-by-step explanation:

1. (a+3)(a-3)=a^2-3^2=a^2-9
2. (5xy-7)(5xy+7)=5xy^2-7^2=5xy^2-49
3. 105=(100+5)^2-(100-5)^2=100^2-5^2=75