Question 1 Report
When \(f(x) = 2x^{3} + mx^{2} + nx + 11\) is divided by \(x^{2} + 5x + 1\), the quotient is \(2x - 5\) and the remainder is \(30x + 16\). Find the values of m and n.
By the division identity, dividend = divisor \(\times\) quotient + remainder:
\[ f(x) = (x^2 + 5x + 1)(2x - 5) + (30x + 16). \]
Expand the product:
\[ (x^2+5x+1)(2x-5) = 2x^3 - 5x^2 + 10x^2 - 25x + 2x - 5 = 2x^3 + 5x^2 - 23x - 5. \]
Add the remainder:
\[ f(x) = 2x^3 + 5x^2 - 23x - 5 + 30x + 16 = 2x^3 + 5x^2 + 7x + 11. \]
Compare with \( f(x) = 2x^3 + mx^2 + nx + 11 \):
\[ m = 5, \qquad n = 7. \]
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