Question 1036319
a.  This does fall to the left and rise to the right.  (x^3) is - for negative x.
{{{graph(300,200,-10,10,-100,100,4x^3+7x^2+5)}}}
b. This is an odd powered function with a negative sign in front of it, so it will do the opposite of the first one.
{{{graph(300,200,-10,10,-100,100,-6x^5-2x^4-8x+2)}}}
I will edit c. as -2(x-2)^2+x+4
c.  This will fall to the left and fall to the right.  It has an even powered function with a negative sign in front.
{{{graph(300,200,-10,10,-100,100,-2(x-2)^2+x+4))}}}