The x-intercept is the value of x when y is equal is zero. It is the point in the x-axis intersected by the line. The y-intercept is the value of y when x is zero. It is where the line intersects in the axis. Therefore, for the given equation:
y=−12x+4
y=−12(0)+4 = 4<--------y-intercept
0=−12x+4
x = 1/3 <--------x-intercept