А) x^2/5y и z-3/y^2 <=> (y*x^2) / 5y^2 и (5z-15) / 5y^2
20.45
Получили:
40.9:2=20.45
Pervoe i vtoroe. Reshenie.
(5-t)(-t-5)-(4+t)² = (-t)²-25-(16+8t+t²) = (-t)²-25-16-8t-t² = - 41 - 8t
3x^2 + y = 4
2x^2 - y = 1
-------------------- + сложим
5x^2 = 5
x^2 = 1
x = ± 1
1) y = 4 - 3x^2 = 4 - 3*(-1)^2 = 4 - 3 = 1
x = - 1
2) y = 4 - 3x^2 = 4 - 3*1^2 = 4 - 3 = 1
x = 1
Ответ
( - 1; 1)
( 1; 1)