Question

9)
10)
solve for x.
11)
12)
find the missing length indicated.
13)
14)
15)
16)
solve for x.
17)
18)

Explanation:

Problem 9:

Step1: Set up proportion

$\frac{22}{x}=\frac{9}{11}$

Step2: Cross multiply

$9x=22\times11$

Step3: Solve for x

$x=\frac{242}{9}\approx26.89$

Problem 10:

Step1: Set up proportion

$\frac{?}{28}=\frac{8}{16}$

Step2: Simplify & solve

$?=28\times\frac{8}{16}=14$

Problem 11:

Step1: Set up proportion

$\frac{22}{7+14x}=\frac{25}{35}$

Step2: Simplify ratio

$\frac{22}{7+14x}=\frac{5}{7}$

Step3: Cross multiply

$5(7+14x)=22\times7$

Step4: Expand & solve

$35+70x=154$
$70x=119$
$x=\frac{119}{70}=1.7$

Problem 12:

Step1: Set up proportion

$\frac{2x-10}{9}=\frac{4}{10}$

Step2: Simplify ratio

$\frac{2x-10}{9}=\frac{2}{5}$

Step3: Cross multiply

$5(2x-10)=18$

Step4: Expand & solve

$10x-50=18$
$10x=68$
$x=6.8$

Problem 13:

Step1: Set up proportion

$\frac{?}{36}=\frac{30}{15}$

Step2: Simplify & solve

$?=36\times2=72$

Problem 14:

Step1: Set up proportion

$\frac{?}{12}=\frac{14}{8}$

Step2: Simplify & solve

$?=12\times\frac{7}{4}=21$

Problem 15:

Step1: Set up proportion

$\frac{?}{30}=\frac{39}{24}$

Step2: Simplify & solve

$?=30\times\frac{13}{8}=48.75$

Problem 16:

Step1: Set up proportion

$\frac{?}{7}=\frac{20}{28}$

Step2: Simplify & solve

$?=7\times\frac{5}{7}=5$

Problem 17:

Step1: Set up proportion

$\frac{2x-5}{21}=\frac{10}{24}$

Step2: Simplify ratio

$\frac{2x-5}{21}=\frac{5}{12}$

Step3: Cross multiply

$12(2x-5)=105$

Step4: Expand & solve

$24x-60=105$
$24x=165$
$x=\frac{55}{8}=6.875$

Problem 18:

Step1: Set up proportion

$\frac{x-1}{12}=\frac{5}{6}$

Step2: Cross multiply

$6(x-1)=60$

Step3: Solve for x

$x-1=10$
$x=11$

Answer:

1. $\boldsymbol{x=\frac{242}{9}\approx26.89}$
2. $\boldsymbol{14}$
3. $\boldsymbol{x=1.7}$
4. $\boldsymbol{x=6.8}$
5. $\boldsymbol{72}$
6. $\boldsymbol{21}$
7. $\boldsymbol{48.75}$
8. $\boldsymbol{5}$
9. $\boldsymbol{x=\frac{55}{8}=6.875}$
10. $\boldsymbol{x=11}$