Question

Dadas as retas r:2x+y-4=0 e s: 2x-y+1=0 indique o ponto em que elas se interceptam?

Answer 1

 2x+y-4=0   ==>2x=4-y
 2x-y+1=0  ==>2x=y-1

4-y =y-1
2y=5
y=5/2 <<<<<<<<<<<<<<<<<<<<<

2x+5/2-4=0

2x+5/2-8/2=0

2x-3/2=0

2x=3/2

x=3/4  <<<<<<<<<<<<<<<<<

Ponto ( 3/4 , 5/2)