Since the formula is y=mx+b, we can substitute the point (7,6) into it and get 6=6m+b. Substituting the other point, we get 2=9m+b.
Subtract the two equations from each other to find m, and we can get rid of b. The new equation is:
-3m = 4
m= -4/3
Plugging this into 6=6m+b,
6=6*(-4/3) +b
6= -8+b
b=14
Plugging the m and b values into the original formula,
y= -4/3x+14