Question

Решите систему уравнений.
х^2+у=7
2х^2-у=5

Answer 1

$+ \left \{ {{ x^{2} +y=7} \atop {2 x^{2} -y=5}} \right.$
____________
3x² = 12
x² = 4
x₁ = 2         x₂ = - 2
y₁ = 7 - x² = 7 - 2² = 7 - 4 = 3
y₂ = 7 - x² = 7 - (- 2)² = 7 - 4 = 3
Ответ : (2 ; 3) , (- 2 ; 3)

Answer 2

${x}^{2} + y = 7 \\2 {x}^{2} - y = 5$

$2 {x}^{2} + {x}^{2} + y - y = 7 + 5 \\3 {x}^{2}=12 \\ {x}^{2} = \frac{12}{3} \\ {x}^{2} = 4 \\x = \sqrt{4} \\x_{1,2}= \frac{ + }{} 2$
${2}^{2} + y =7 \\4 + y =7 \\ y = 7 - 4 \\y_{1} = 3 \\ { (- 2) }^{2} + y = 7 \\y_{2} =3.$
$Ответ : (2; 3); (-2; 3 ) .$