y-Intercept

The y-intercept is the intersecting point
of the graph and the y-axis.

The y-intercept is the intersecting point
of the linear equation 3x + 4y = 12 and the y-axis.

And the y-axis is x = 0.

So put x = 0 in the linear equation 3x + 4y = 12.
Then 3⋅0 + 4y = 12.

Then solve the equation.

Then y = 3.

So y = 3 is the y-intercept.

This is the graph of the linear equation 3x + 4y = 12.

By the above calculation,
you found that the y-intercept is y = 3.