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Calculate the indicated value of each function.

If f(x)=
(15-15x+14x^2)/(28-x), find f(8)

1 Answer

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Answer:

To find f(8), we can substitute x = 8 into the expression for f(x):

f(x) = (15 - 15x + 14x^2) / (28 - x)

f(8) = (15 - 15(8) + 14(8)^2) / (28 - 8)

f(8) = (15 - 120 + 896) / 20

f(8) = -209/4

Therefore, f(8) is equal to -209/4.

Explanation:

The given function is:

f(x) = (15 - 15x + 14x^2) / (28 - x)

To find f(8), we simply substitute x = 8 into the expression for f(x):

f(8) = (15 - 15(8) + 14(8)^2) / (28 - 8)

Note that we replaced every occurrence of x in the expression for f(x) with 8, since we are evaluating the function at x = 8.

Next, we simplify the expression inside the parentheses:

15 - 15(8) + 14(8)^2 = 15 - 120 + 896 = 791

Similarly, we simplify the denominator:

28 - 8 = 20

Substituting these values back into the expression for f(8), we get:

f(8) = 791 / 20

This expression cannot be simplified any further, so we leave the answer as a fraction.

Therefore, f(8) is equal to -209/4.

User Chris Stryker
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