Find the number of times r is a root of P(x)=0.
1. P(x)=x^4+4x^3-16x-16; r=-2
2. P(x)=x^5+3x^4+2x^3-2x^2-3x-1; r=-1
3. When x^3-5x^2+4x+5 is divided by x-c, the quotient is x^2-3x-2 and the remainder is 1. Find c.
Thanks
1. P(x)=(x-2)(x+2)^3 3 times
2. P(x)=(x-1)(x+1)^4 4 times
3. x^3-5x^2+4x+5=(x^2-3x-2)(x-c)+1=>5=2c+1
c=2