Ответ:

Объяснение:

1) √x - √y = 4

(√x-√y)(√x+√y) = 32

√x - √y = 4

√x + √y = 8

сложим между собой

2√x = 12

√x= 6

x = 36

6-√y = 4

√y = 2

y =4

2) √y = 2√x - 5

√x(2√x - 5) = 3

2x-5√x -3 = 0

√y = 2√x - 5

2x-5√x -3 = 0

D = 25+24 = 49

√x  =  (5±7)/4

√x₁ = -1/2

√x₂ = 3

x₁ = 1/4

√y₁ =  -6

y₁ = 36

x₂ = 9

√y₂ =  1

y₂ =  1

3) √x + √y = 8

(√x-√y)(√x+√y) = 16

√x + √y = 8

√x - √y = 2

сложим

2√х = 10

√y = √x -2

√х = 5

√у = 3

x = 25

y = 9