(4,7)(0,7)
notice how ur points have the same y values....this means this is a horizontal line with a slope of 0.
equation is : y = 7...or y = 0x + 7...but we need it in standard form...
0x + y = 7 <== standard form

Slope of the given line is :
where ,
let's solve :
Slope = -3 / 4