Question

Resolva:

2 (x+y)=5 (x-y)
x/2-y=2

Answer 1

x/2 - y = 2
x/2 - 2 = y
(x - 4)/2 = y
x - 4 = 2y
x = 2y + 4


2x + 2y = 5x - 5y
2y + 5y = 5x - 2x
7y = 3x
7y = 3×(2y + 4)
7y = 6y + 12
7y - 6y = 12

y = 12



x = 2×(12) + 4
x = 24 + 4

x = 28

Answer 2

• 2x + 2y = 5x - 5y
→ 7y = 3x
• x - 2y = 4
→ x = 4 + 2y

7y = 3 (4 + 2y)
7y - 6y = 12
y = 12

x = 4 + 2 (12)
x = 28

S = {28, 12}