Question

Решите систему уравнений

Answer 1

{3x - 5y = 23 (* 3)
{2x + 3y = 9  (* 5)

{9x - 15y = 69
+
{10x + 15y = 45

9x + 10x = 69 + 45
19x = 114
x = 114 : 19
x = 6

10 * 6 + 15y = 45
60 + 15y = 45
15y = 45 - 60
15y = -15
y = -1

Ответ: (6; -1)

{6x + 5y = 0
{2x + 3y = -8 (* 3)

{6x + 5y = 0
-
{6x + 9y = -24

5y - 9y = 0 - (-24)
-4y = 24
y = 24 : (-4)
y = -6

6x + 5 * (-6) = 0
6x + (-30) = 0
6x = 0 + 30
6x = 30
x = 30 : 6
x = 5

Ответ: (5; - 6)