Question 873332
The slope looks like -1/2, and the x-intercept is 4.  Use any form of linear equation that you want to determine corresponding constant value.  


USING SLOPE-INTERCEPT FORM
{{{y=mx+b}}}
{{{b=y-mx}}}
{{{b=0-(-1/2)4}}}
{{{b=+2}}}
Equation: {{{highlight(y=-(1/2)x+2)}}}, which is not showing exactly "x+2".


USING POINT-SLOPE FORM
Any of the given points will work, but x-intercept will be convenient;
{{{y-0=-(1/2)(x-4)}}}
{{{highlight(y=-x/2+2)}}}, which is equivalent to the other equation found.