Complete the square to determine the minimum or maximum value of the function defined by the expression.

−x² + 10x + 5

a. maximum value at 30
b. minimum value at 30
c. maximum value at −30
d. minimum value at −30

provide a full explanation, you!

A. maximum value at 30

Step-by-step explanation:

−x² + 10x + 5

First, factor out the leading coefficient from the first two terms:

-1 (x² − 10x) + 5

Take half of the next coefficient, square it, then add and subtract the result.

(-10/2)² = 25

-1 (x² − 10x + 25 − 25) + 5

-1 (x² − 10x + 25) + 25 + 5

-1 (x² − 10x + 25) + 30

Factor the perfect square.

-1 (x − 5)² + 30

The equation is now in vertex form.  This is a downwards parabola with a vertex at (5, 30).  Since the parabola points down, the vertex is a maximum.

answer: the answer is one of

step-by-step explanation:   we are given to write a proper fraction where the whole is divided into an even number of equal parts less than ten, and an odd number of those parts exist.

an even number less than 10 may be one of 2, 4, 6 or 8. so, the whole may be one of these four evens.

now, an odd number of these parts must exist, so the numerator must be an odd number, one of 1, 3, 5 or 7. it cannot be 9 because then the fraction will become improper.

thus, our fraction may be one of the following