N1
1)y'=20x^3 -7x +1
2)y=(x+5)(x-3)= x^2-3x+5x-15=x^2+2x-15
y'=2x+2
3)y=x^3/(2x+4)
y'=[ 3x^2*(2x+4) - x^3*2 ]/ (2x+4)^2 = [ 6x^3+12x^2-2x^3 ] / (2x+4)^2 =
=[ 4x^3+12x^2 ] /(2x+4)^2
4)y=(5x+9)^9
y'=9*(5x+9)^8 * (5x+9)' = 9*(5x+9)^8 *5= 45*(5x+9)^8
N2
f'(x)=3x^2-14x+2=2
3x^2-14x+2-2=0
3x^2-14x=0
x*(3x-14)=0
x=0 3x-14=0
3x=14
x=14/3=4 2/3