I'm sorry that I'm not in calculus, but hopefully I can help.
Personally, I would choose: D.) x; in the second equation ;
because it has easier numbers to figure out, you'll get it eventually...
It’s 16 look at it a bit closer if you get confused step away and clear your mind a bit
Again A because that rule applies to what I said before in the other 2 questions you asked.
Group and factor
undistribute then undistribute again
remember
ab+ac=a(b+c)
this is important
6d^4+4d^3-6d^2-4d
undistribute 2d
2d(3d^3+2d^2-3d-2)
group insides
2d[(3d^3+2d^2)+(-3d-2)]
undistribute
2d[(d^2)(3d+2)+(-1)(3d+2)]
undistribute the (3d+2) part
(2d)(d^2-1)(3d+2)
factor that difference of 2 perfect squares
(2d)(d-1)(d+1)(3d+2)
77.
group
(45z^3+20z^2)+(9z+4)
factor
(5z^2)(9z+4)+(1)(9z+4)
undistribuet (9z+4)
(5z^2+1)(9z+4)
