#### Answer

(1,4)

#### Work Step by Step

$3x+y=7$
$4x-y=0$ $\longrightarrow$ solve for y by adding y to both sides
$4x-y+y=0+y$
$4x=y$
Substitute 4x for y in the first equation.
$3x+4x=7$ $\longrightarrow$ simplify
$7x=7$ $\longrightarrow$ divide both sides by 7
$7x\div7=7\div7$ $\longrightarrow$ simplify
$x=1$
Substitute 1 for x in the second equation.
$4(1)-y=0$ $\longrightarrow$ simplify and add y to both sides
$4-y+y=0+y$ $\longrightarrow$ simplify
$4=y$