how to find y intercept of line y= 4x+12

For any equation in x and y,

to find the x-intercept, let y = 0 in the equation
to find the y-intercept , let x = 0 in your equation

of course you should be familiar with the form y = mx + b
where b is the y-intercept
For yours it would be 12

y = mx+b

is called the slope-intercept form for a reason ...

To find the y-intercept of a line, you need to identify the value of y when x is equal to zero.

In your equation, y = 4x + 12, you can substitute x with 0:

y = 4(0) + 12

When you simplify the equation, you find:

y = 0 + 12

Therefore, the y-intercept of the given line is 12.