equation of a line with an x-intercept of 4 and a slope of -1/2

Question

usually this is y-intercept but i dont know how to do x-intercept

Answer 1

If,    y = mx + c        , is the equation of a straight line, where m=gradient (i.e. the slope), and c=y-intercept.

y = -x/2 + c

The x-intercept is when the line intercepts thex-axis, i.e. when  y=0 and x=4. Put this into equation.

So, 0 = -4/2 + c

0 = -2 + c

c = 2

 

So, the equation becomes:

y = -x/2 + 2