Equations in slope-intercept form follow a certain format.
y= mx+ b
In this form, m is the slope and b is the y-intercept. The line has a slope of - 2 which means that we can substitute m= - 2.
y= - 2x+ b
By substituting the given point ( 3, 0) into the above equation for x and y, we can solve for y-intercept b.