Question

The points (3,r) and (−7,3) lie on a line with slope 3. Find the missing coordinate r

Answer 1

dy/dx=y2-y1/x2-x1

Answer 2

so 3-r/-7-3=3

Answer 3

general equation for a line is : y=ax+b
a is the slope, hence a=3

We know that when x=-7, y=3

let's plug these values to the general equation:

Y=3*x+b >>> 3= 3*(-7) +b therefore b is 24


know let's find r for x=3

r=3*3+24=33