teamnumber1-hw1-8-1-DirectVariation

__**Pg. 354-355 Numbers 3,5,8,9,12**__

P=9 Q=7.5 9=K(7.5) - **Plug in numbers** 9/7.5 = K (7.5)/7.5 – **Divide to isolate K**
 * 3. P=KQ**
 * k= 1.2**

24=1.2 Q – **Plug in K and other known number** 24/1.2= 1.2Q/1.2 -**Solve for unknown**
 * Q= 20**

s=12 r=2 12=K(2 squared) – **Plug in and solve for K** 12= 4k – **Divide by 4 on both sides to isolate K**
 * 5. S=K (R squared)** – **Set up problem**
 * K=3**

S= 25(3) – **Plug in K and the other known number**
 * S=75**

w=9 x=2 9= K (2(2)-1) **– Plug in variables** 9=K(3) - Solve
 * 8. W=K(2x-1)**
 * K=3** – **Divide by three to isolate K**

15= 3(2x-1) – **Plug in K to original equation with Givens** 15= 6x-3**– -solve** 18=6x -**Add three to both sides**
 * x=3 – Divide 6 on both sides to isolate x.**

9. A/B = B/C 2/X =X/18 – **Plug in variables** X squared = 36 – **Cross Multiply**
 * X=6** - **Square 36 to isolate x**

12. A/B = B/C 5/b = b/15 **– Plug in givens for A and C** B squared = 75 **– Cross multiply**
 * B = 3 root 5** **- Divide 75 by its square to isolate b**

__**Pg. 356 #3, 9, 15**__

5400/120,000=120,000k/120,000 **Solve for k** k=.045
 * 3.** 5400=k(120,000) **Substitute the given information into the model**

y=.045(145,000) **Plug k and the other given number into the new model and solve**
 * y=$6,525**

15/3.6=3.6k/3.6 **Solve for k** k=4.2
 * 9.** 15=k(3.6) **Substitute the given information into the model**

y=4.2(6) **Plug in k and the other given number into the new model and solve**
 * y=25.2kg**

4=1/4k **Simplify the equation** 4(4)=1/4k(4) **Solve for k** k=16
 * 15.** 4=k(.5 squared) **Substitute the given information into the model**

d=16(2.5 squared) **Substitute the given information into the model** d=16(6 1/4) **Simplify the equation** d=100 **Solve for the variable** 100-4=**96 ft. Subtract the first distance from the new one to find out how much further it needed to go**