The only difference between these quadratic functions are coefficients (-2 and 1/3)
When coefficient is positive (1/3) the functions open upward (like u shape)
When coefficient is negative (-2) the functions open downward (like n shape)
Also regardless sign of the coefficient if the number is greater that function is narrower
so; graph of -2(x+3)(x-7) is narrower (just ignore the sign and think you compare 2 and 1/3)
Hope that helps