Hi, i'm trying to figure out how my professor got these answers for these problems. I appreciate all help! Thank you!

#1. Find the second derivative. (x³+5)⁵ and his answer is 30x(x³+5)³ (7x³+5)

#2. Differentiate and simplify, { (x-1)(x²+x+1)}/ x³ and his answer was 3/x²

#3. Differentiate and simplify, x²+x-2/ x³+6 his answer was -x⁴-3x³+6x²+12x+6/( x³+6)²

#4.Differentiate and simplify, x³-x²-3/ x⁵+3 his answer was 2x⁷+3x⁶+15x⁴+9x²-6x/ (x⁵+3)²

#5.Solve for x, 5+e^x+1=20 his answer was x=l+ ln 15