Question

1)5√75-2√27
2)3√20+5√45-2√80
3)√ 176^2-112^2/98
4)√3-3/√5-√15
5)x√x+y√y/√x+√y
6)√81a+√9a-√49a
7)4x^2-2x√2x+2x-√2x+1.при х>0
8)1/√5-√3+2
9)1/5+2√6+1/5-2√6 плиззз

Answer 1

1) 5√75 - 2√27 = 5√(25*3) - 2√(9*3) = 25√3 - 6√3 = 19√3

2) 3√20 + 5√45 - 2√80 = 3√(4*5) + 5√(9*5) - 2√(16*5) =
                                 = 6√5 + 15√5 - 8√5 = 13√5
3) √176² - (112)²/98 = √(16*11)² - (16*7)²/(49*2) = 16*11 - (16² * 7²)/(7² * 2) =
                             = 2⁴ *11 - 2⁷ = 2⁴(11 - 2³) = 16*3 = 48

6) √81a + √9a - √49a = 9√a + 3√a - 7√a = 5√a
9) 1/(5+2√6) + 1/(5-2√6) = ((5-2√6)+(5+2√6)) / (5-2√6)*(5+2√6) =
                                   = 10/(5² - (2√6)²) = 10/(25-24) = 10