Question

Me ajudeem por favor a resolver essa questao
{x-3y=7
{5x-3y=11

Answer 1

x-3y=7 ⇒ x=7+3y
5x-3y=11

5x-3y=11 ⇒ 5.(7+3y)-3y=11 ⇒ 35+15y-3y=11 ⇒12y=11-35 ⇒ y=-2

x-3y=7 ⇒ x-3.(-2)=7 ⇒ x=7-6 ⇒ x=1

Answer 2

x - 3 y = 7

5 x - 3 y = 11
-x  + 3 y =-7 ( multiplicando por -1)
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4 x = 4
x = 4/4
x = 1
x- 3 y  =7
1 - 3 y = 7 
-3 y = 7 - 1
-3 y = 6
y = 6/-3
y = -2