x(2x - 7) = 3 simplify
2x^2 - 7x - 3 = 0
2 ( x^2 - (7/2)x - 3/2) = 0 divide through by 2
x^2 - (7/2)x - 3/2 = 0 complete the square on x
x^2 - (7/2)x = 3/2
x^2 - (7/2)x + 49/16 = 3/2 + 49/16
(x - 7/4)^2 = (24 + 49) / 16
( x - 7/4)^2 = ( 73) / 16 take both roots
x - 7/4 = ±√(73) / 4
x = [ 7 ±√(73) ] / 4
m = 7 n = 73 and p =4
So m + n + p = 84