SOLUTION: if f(x)=2x^3+Ax^2+8x-9 and f(2)=5, what is the value of A?

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Question 499378: if f(x)=2x^3+Ax^2+8x-9 and f(2)=5, what is the value of A?
Answer by Gogonati(855) About Me  (Show Source):
You can put this solution on YOUR website!
f%282%29=2%2A2%5E3%2BA%2A2%5E2%2B8%2A2-9=4%2AA%2B23, since f(2)=5 we have 4*A+23=5, solving this
equation we get:4*A=-18 => A=-4.5