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If f(x)=x^3-5x^2+kx-3 and f(3)=-15, find k

User Alex Suo
by
4.6k points

2 Answers

4 votes

Answer:

The answer to your question is: K = 12

Explanation:

Data

f(x) = x³ - 5x² + kx - 3

f(3)=-15, find k

Process

15 = (3)³ - 5(3)² + k(3) - 3 Substitution

15 = 27 - 45 + 3k -3 Simplify

15 = -21 + 3k

15 + 21 = 3k

3k = 36

k = 36 / 3

k = 12 result

User CP Sean
by
4.0k points
1 vote

Explanation:

f(x)=x^3-5x^2+kx-3

f(3) = 3^3 - 5×3^2 + k×3 -3

=27 - 5×9 +3k - 3

=24 -45 + 3k

-15 =- 21 + 3k

-15 + 21 = 3k

6 = 3k

divide both by 3

k = 2

User Shreyas D
by
5.2k points