Question

решите системы уравнений
$left { {{( sqrt{x} -3)(y-6)=0} atop { sqrt{x} +5y=8}} right.$
$left { {{ sqrt{4 x^{2} +7y+2}=4 } atop { sqrt{3 x^{2} +7y+2}=4 }} right.$
$left { {{ sqrt{x+y}=8 } atop { frac{ sqrt{x+y} }{x}=4 }} right.$

Answer 1

1)$left { {{ (( sqrt{x} -3)(y-6)=0} atop { sqrt{x} +5y=8}} right.$
$sqrt{x} = 8-5y$
((8-5y)-3)(y-6)=0
-5y^2 + 35y-30=0
D=25^2
y=6; y=1
$sqrt{x} = 8-5y$
x=9; x=484

3)√(x+y) = 8
    √(x+y) / x =4
8/x=4
x=2
√(2+y) = 8
2+y=64
y=62


2)√(4x^2 + 7y +2) =4
   √( 3x^2 +7y +2) =4
x^2 =0
x=0
√(4x^2 +7y+2) = 4
√(7y+2) = 4
7y+2=16
7y=14
y=2