Question

Система уравнений:
7x – 3y = 13,
x – 2y = 5; и

4х – у = 11,
6х – 2у =12; (дам 27)

Answer 1

7x-3y=13
x=5+2y

7(5+2y)-3y=13
35+14y=-3y=13
35+11y=13
11y=13-35
11y=-22
y=-2 x=5+2×(-2)=1
Ответ: (1; -2)


y=-11+4x
6x-2y=12

6x-2(-11+4x)=12
6x+22-8x=12
-2x+22=12
-2x=12-22
-2x=-10
x=5 y=-11+4×5=9
Ответ: (5; 9)