Question

Find the missing value.
(√24-√k)(√24+√k)=5

Answer 1

• k = 19

Explanation:

Identity

• (a + b)(a - b) = a² - b²

Simplifying the LHS (Left Hand Side)

• (√24-√k)(√24+√k)
• (√24)² - (√k)²
• 24 - k

Equating to the RHS

• 24 - k = 5
• k = 24 - 5
• k = 19

Answer 2

19

Explanation:

`(√(24) -√(k) )(√(24) +√(k) )\\\\As,\\\\\hookrightarrow a^(2) -b^(2) =(a+b)(a-b)\\\\Subtitute:\\\\a=√(24) \\\\b=√(k) \\\\Now,\\\\\hookrightarrow (√(24) -√(k) )(√(24) +√(k) )=5\\\\\hookrightarrow (√(24) )^(2) -(√(k) )^(2) =5\\\\\hookrightarrow 24-k=5\\\\\hookrightarrow 24-5=k\\\\\hookrightarrow 19`