The graph of the function f(x) = (x − 3)(x + 1) is shown.

1 answer:

3 0

The expression that describes all of the values for which the graph is positive and decreasing is all real values of x where x < -1

<h3>Which describes all of the values for which the graph is positive and decreasing?</h3>

The equation of the function is given as:

f(x) = (x - 3)(x + 1)

When the value of the graph is positive, we have:

f(x) > 0

So, the function becomes

(x - 3)(x + 1) > 0

Split the above inequality

x - 3 > 0 and x + 1 > 0

Solve for x in the inequalities

x > 3 and x > -1

Hence, the expression that describes all of the values for which the graph is positive and decreasing is all real values of x where x < -1

You might be interested in

The number 64 has the property that it is divisible by its units digit. How many whole numbers between 10 and 50 have this prope

sineoko [7]

Answer:

$\large \boxed{17}$

Step-by-step explanation:

Let's call the numbers "<em>tu</em>", where<em> t</em> is the tens digit and <em>u</em> is the units digit.

We can solve this by the "brute force" method — examining each number to see if it satisfies the conditions.

$\begin{array}{cccl}\mathbf{u}&\mathbf{tu}& \textbf{Divisible by u} & \\0 &20, 30, 40 & 0 & \text{Division by zero is impossible}\\1 & 11, 21, 31, 41 & 4& \text{All numbers are divisible by one}\\2 & 12, 22, 32, 42 & 4 & \text{All even numbers are divisible by two}\\3 & 13, 23, 33, 43 & 1 &\text{Only 33 is divisible by three}\\4 & 14, 24, 34, 44 & 2 & \text{Only 24 and 44 are divisible by four}\\5 & 15, 25, 35, 45 & 4 & \text{Numbers ending in 5 are divisible by five}\\\end{array}$

$\begin{array}{cccl}6 & 16, 26, 36, 46 & 1 & \text{Only 36 is divisible by six}\\7 & 17, 27, 37, 47 & 0 & \text{None of the numbers is divisible by seven}\\8 & 18, 28, 38, 48 & 1 & \text{Only 48 is divisible by eight}\\9 & 19, 29, 39, 49 & 0 & \text{None of the numbers is divisible by nine}\\& \textbf{TOTAL =} &\mathbf{17}& \\\end{array}\\\text{$\large \boxed{\mathbf{17}}$ numbers between 10 and 50 are divisible by their units digit}$