2 и 5 срочно!!!!!!!! Спасиибо заранее

№ 2
3x + 2y = 8
-3x + 5y = 6
Складываем

7y = 14
y = 2

3x + 2*2 = 8
3x = 4
x = 4/3

(1 (1/3); 2) 

№ 5
Замена
y = 2x + 1
(2x + 1)^2 - 4x - 2 = 0
4x^2 + 4x + 1 - 4x - 2 = 0
4x^2x = 1
x^2x = 1/4
x1 = - 1/2
x2 = 1/2

y1 = 2*(-1/2) + 1 = 0
y2 = 2*(1/2) + 1 = 2

(-1/2;0)  (1/2; 2)