Respuesta :
3x - 5y = 20
(5; y) - put x = 5 to the equation
3 · 5 - 5y = 20
15 - 5y = 20 |-15
-5y = 5 |:(-5)
y = -1
Answer: (5; -1)
(x; 2) - put y = 2 to the equation
3x - 5 · 2 = 20
3x - 10 = 20 |+10
3x = 30 |:3
x = 10
Answer: (10; 2)
(5; y) - put x = 5 to the equation
3 · 5 - 5y = 20
15 - 5y = 20 |-15
-5y = 5 |:(-5)
y = -1
Answer: (5; -1)
(x; 2) - put y = 2 to the equation
3x - 5 · 2 = 20
3x - 10 = 20 |+10
3x = 30 |:3
x = 10
Answer: (10; 2)