Question

x-2y=1 3x+y=3 sustitucion

Answer 1

x - 2y = 1
x = 1 + 2y

3x + y = 3

3(1 + 2y) + y = 3
3 + 6y + y = 3
7y = 0
y = 0

x = 1 + 2*0
x = 1