Verified answer

log(a^k) b^n = n/k*log(a) b

log (c) (ab) = log(c) a + log(c) b

(a + b)² = a² + 2ab + b²

a² - b² = (a - b)(a + b)

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log(√5) 25/(√3 + √14) = log(5^1/2) 5^2/(√14 + √3) = log(5) 5^4 / (√14 + √3)² = log(5) 5^4 - log(5) (√14 + √3)² = 4 - log(5)(√14 + √3)²

log(0.2) 1/(17 + 2√42) = log (1/5) 1/(14 + 2√(14*3) + 3) = - log(5) 1/(√14 + √3)² = - log(5) 1 + log(5) (√14 + √3)² = log(5) (√14 + √3)²

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4 - log(5)(√14 + √3)² +  log(5)(√14 + √3)² = 4

ответ 4