y'=(x-1)'*(x+3)+(x-1)(x+3)'=x+3+x-1=2x+4
y'=5*3x^2-3*5x^4=15x^2-15x^4=15x^2(1-x^2)
y'=4*5x^4-4*4x^3=20x^4-16x^3=4x^3(5x-4)
y'=(x-1)'*(x+3)+(x-1)(x+3)'=x+3+x-1=2x+4
y'=5*3x^2-3*5x^4=15x^2-15x^4=15x^2(1-x^2)
y'=4*5x^4-4*4x^3=20x^4-16x^3=4x^3(5x-4)