Question

rozwiąż równanie metodą podstawiania :

a) 3x - 2y = 5

2x - y = 4

b) 2x + 9y = -9

-3x + 3y = 8

c) 2x + 3y = 4

8x - 5y = -1

Answer 1

a 
3x - 2y = 5 
2x - y = 4 / (-2)

3x - 2y = 5 
-4x + 2y = -8

x = -3
y = -10

b

2x + 9y = -9
-3x + 3y = 8 / (-3)

2x + 9y = -9
9x- 9y = -24

11x = -33

x = -3
y = 1/3


c

2x + 3y = 4  /(-4)
8x - 5y = -1

-8x - 12y = -16
8x - 5y = -1

 

-17y = -17
y = 1

x = 0,5