17 8th Grade Spelling Worksheets - Free PDF at worksheeto.com - Free Printable

Let's solve each problem step by step:

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Problem 1: Use the following function rule to find \( f(9) \): \( f(x) = 2x - 9 \)

#### Solution:
The function is given as \( f(x) = 2x - 9 \). To find \( f(9) \), substitute \( x = 9 \) into the function:

\[
f(9) = 2(9) - 9
\]

First, calculate \( 2 \times 9 \):

\[
2 \times 9 = 18
\]

Next, subtract 9 from 18:

\[
18 - 9 = 9
\]

So, the value of \( f(9) \) is:

\[
\boxed{9}
\]

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Problem 2: What % of 60 is 27?

#### Solution:
To find what percentage 27 is of 60, use the formula:

\[
\text{Percentage} = \left( \frac{\text{Part}}{\text{Whole}} \right) \times 100
\]

Here, the "Part" is 27 and the "Whole" is 60. Substitute these values into the formula:

\[
\text{Percentage} = \left( \frac{27}{60} \right) \times 100
\]

First, simplify the fraction \( \frac{27}{60} \):

\[
\frac{27}{60} = \frac{9}{20}
\]

Now, multiply by 100:

\[
\frac{9}{20} \times 100 = 9 \times 5 = 45
\]

So, 27 is \( 45\% \) of 60:

\[
\boxed{45}
\]

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Problem 3: Find the unit rate: 550 ml for 5 oranges

#### Solution:
To find the unit rate (ml per orange), divide the total volume (550 ml) by the number of oranges (5):

\[
\text{Unit rate} = \frac{550 \text{ ml}}{5 \text{ oranges}}
\]

Perform the division:

\[
\frac{550}{5} = 110
\]

So, the unit rate is:

\[
\boxed{110 \text{ ml/orange}}
\]

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Problem 4: Solve for \( y \): \( 5y - (-2) < 17 \)

#### Solution:
Simplify the expression \( 5y - (-2) \):

\[
5y - (-2) = 5y + 2
\]

So the inequality becomes:

\[
5y + 2 < 17
\]

Next, isolate \( 5y \) by subtracting 2 from both sides:

\[
5y + 2 - 2 < 17 - 2
\]

\[
5y < 15
\]

Now, solve for \( y \) by dividing both sides by 5:

\[
\frac{5y}{5} < \frac{15}{5}
\]

\[
y < 3
\]

So, the solution is:

\[
\boxed{y < 3}
\]

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Problem 5: Evaluate the expression for \( x = 6 \) and \( y = 4 \): \( xy - 3y \)

#### Solution:
The expression is \( xy - 3y \). Substitute \( x = 6 \) and \( y = 4 \):

\[
xy - 3y = (6)(4) - 3(4)
\]

First, calculate \( 6 \times 4 \):

\[
6 \times 4 = 24
\]

Next, calculate \( 3 \times 4 \):

\[
3 \times 4 = 12
\]

Now, subtract:

\[
24 - 12 = 12
\]

So, the value of the expression is:

\[
\boxed{12}
\]

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Final Answers:

1. \( \boxed{9} \)
2. \( \boxed{45} \)
3. \( \boxed{110 \text{ ml/orange}} \)
4. \( \boxed{y < 3} \)
5. \( \boxed{12} \)