Expanding (2 + 7x)(2 - 7x)
This expression is a classic example of a difference of squares. Let's break it down:
Understanding the Difference of Squares Pattern
The difference of squares pattern states: (a + b)(a - b) = a² - b²
In our case, a = 2 and b = 7x.
Applying the Pattern
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Identify 'a' and 'b':
- a = 2
- b = 7x
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Substitute into the pattern:
- (2 + 7x)(2 - 7x) = 2² - (7x)²
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Simplify:
- 2² - (7x)² = 4 - 49x²
Final Result
Therefore, (2 + 7x)(2 - 7x) expands to 4 - 49x².