5 і 6 завдання дуууже треба

5.

1) √(11a²) = |a|√11 = -√11

2) √(13b²) = |b|√13 = b√13

3) √(18a⁸) = 3|a⁴|√2 = 3a⁴√2

4) √(-a⁷) = √(-a·a⁶) = |a³|√(-a) = -a³√(-a), a ≤ 0.

5) √(25a²b) = 5|a|√b = -5a√b

6) √(-a¹⁰b⁵) = √(-a¹⁰b·b⁴) = |a⁵b²|√(-b) = a⁵b²√(-b), b ≤ 0

6. (√y/(√x - √y) - √y/√x) : y/x = √x/(√x - √y)

1) √y/(√x - √y) - √y/√x = (√(yx) - √(yx) + y)/(√x(√x - √y)) = y/(√x(√x - √y))

2) y/(√x(√x - √y)) : y/x = y/(√x(√x - √y)) · x/y = (yx)/(y√x(√x - √y)) = x/(√x(√x - √y)) = (√x)²/(√x(√x - √y)) = √x/(√x - √y)