Question

Resolva os sistemas do 1° grau:
a) 2x-y=1
{
x+3y=11

b)x-y = x+y = 2
--------- --------
2 3

Answer 1

a) y= 2x-1
 x+3(2x-1)=11 --- x+6x-3=11 -- 7x= 14 --- x=2

b)x+y=6 -- x=6-y
 $\frac{6-y-y}{2} = \frac{6-y+y}{3} --- \frac{6-2y}{2} = \frac{6}{3}$
6-2y=4
-2y=-2
y=1

Answer 2

a) 2x-y = 1 => y=2x-1
x+3y=11 => x+3(2x-1)=11 => x+6x-3=11 => 7x=14 => x=14/7 => x=2 e y=2(2)-1=3