Question

simplify (7+√2)(7-√2)​

Answer 1

Step-by-step explanation:

(7+√2)(7-√2)

=7²-√2²

=49-2

=47 Ans.

Answer 2

47

Step-by-step explanation:

Q.

simplify (7 + √2)(7 - √2)

Solution -

(7 + √2)(7 - √2)

=> (7)² - (√2)².....[using identity (a+b)(a-b) = a² - b², here a = 7 & b = √2]

=> 7² - √2²

=> 49 - 2

=> 47

Hence the simplification is 47.

Note :-

Some formulas (identities), you should remember -

• (a + b)² = a² + 2ab + b²
• (a - b)² = a² - 2ab + b²
• a² - b² = (a + b)(a - b)
• a² + b² = (a + b)² - 2ab = (a - b)² + 2ab

hope it helps.