How do you find the value of y that makes (3,y) a solution to the equation $3x-y=4$ ?

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Answer 1 · 2015-04-09T13:40:51

If (3,y) is a solution to $3x-y=4$ , we can substitute $x=3$ in the equation.

We get

$(3*3) - y = 4$

$9 - y = 4$

Transposing 9 to the right hand side, we get

$- y = 4 - 9$

$- y = -5$

Multiplying both sides with $-1$ , we get

$color(green)( y = 5$

How do you find the value of y that makes (3,y) a solution to the equation 3x-y=43x-y=4?