(r^3+6r^2-21r-18) ÷ (r-3)Show in Synthetic Division

Answer:r² + 9r + 6Step-by-step explanation:+3|  +1    +6   -21   -18    |         +3   +27  +18         +1    +9    +6     0Answer: =1r² +9r + 6 + 0 =r² +9r + 6    (simplified)Read on if you want to know how it was done.To do synthetic division, you first need to get the constant of the divisor and change the sign. Then list the coefficients of the dividend.Drop the first coefficient.Multiply it by the divisor, and write the answer under the next coefficient and add. Repeat till the end.The answer should be one degree less, the original polynomial.