Write each of the equations below in standard form (i.e. y = ax^2+bx+c y=ax ​2 ​​ +bx+c):
a. y = 3(x-7)(x+4) y=3(x−7)(x+4)
b. y = 2(x-3)^2 + 5 y=2(x−3) ​2 ​​ +5
c. y = -2(x+3)(x+5) y=−2(x+3)(x+5)
d. y = -3(x-4)^2 + 8y=−3(x−4) ​2 ​​ +8