Rewrite
(7m-3)^2 as (7m-3) (7m-3) (7m-3) (7m-3)
Expand using foil method
7m(7m)+7m. -3 -3 (7m) -3. -3
Simplify 49m^2-42m+9
Use the form ax^2+bx=c to find the values of a,b,and c
a=49, b=-42, c=9
Consider the vertex form of a parabola
a (x+d)^2 +e
Find d
d=-3/7