Answer
$y=-2$
Work Step by Step
$(3,y)$ and $(1,4)$ $;$ $m=-3$
The slope of a line is given by $m=\dfrac{y_{2}-y_{1}}{x_{2}-x_{1}}$, where $(x_{1},y_{1})$ and $(x_{2},y_{2})$ are two points through which the line passes.
In this case, let $(x_{1},y_{1})$ be equal to $(3,y)$ and $(x_{2},y_{2})$ be equal to $(1,4)$.
Substitute the known values into the formula for the slope of a line and solve for $y$:
$-3=\dfrac{4-y}{1-3}$
$-3=\dfrac{4-y}{-2}$
$(-3)(-2)=4-y$
$6=4-y$
$y=4-6$
$y=-2$
