Answer:
Ann would need 3 h to complete the remainder of the Job.
Step-by-step explanation:
Step 1.
The "speed" that each girl has to do the work is determined as:
- Tina:
, it means that Tina complete one twelveth of the job each hour. - Ann:
, it means the Ann completes one eighth of the job each hour.
Step 2.
The amount of work done by Tina in 9 hours, is obtain multiplying by the "speed" calculated in step 1:
Amount of work done=
. It means that <em>Tina completes two thirds of the work in 9 h.</em>
Step 3.
The remaining job is calculated as
. It means that <em>still remains is one third of the job to be completed</em>.
Step 4.
The time required for Ann to complete the job is calculated dividing the remaining of the job by the "speed" of Ann to do the job.
. It means that <em>Ann would complete the job in another 3 hours</em>.
I got

What we know
cos a=-3/5.
sin b=12/13
Angle A interval are between 180 and 270 or third quadrant
Angle B quadrant is between 90 and 180 or second quadrant.
What we need to find
Cos(b)
Cos(a)
What we are going to apply
Sum and Difference Formulas
Basics Sine and Cosines Identies.
1. Let write out the cos(a-b) formula.

2. Use the interval it gave us.
According to the given, Angle B must between in second quadrant.
Since sin is opposite/hypotenuse and we are given a sin b=12/13. We. are going to set up an equation using the pythagorean theorem.
.




so our adjacent side is 5.
Cosine is adjacent/hypotenuse so our cos b=5/13.
Using the interval it gave us, Angle a must be in the third quadrant. Since cos is adjacent/hypotenuse and we are given cos a=-3/5. We are going to set up an equation using pythagorean theorem,
.




so our opposite side is 4. sin =Opposite/Hypotenuse so our sin a =4/5.Sin is negative in the third quadrant so
sin a =-4/5.
Now use cosine difference formula



Hope this helps
Answer:
The answer is 15
Step-by-step explanation:
I did a cross multiply looking like this 3/10 4.50/x
after you multiply and divide you have your answer.
Answer:
I think its No Solution
Step-by-step explanation:
Hope it helps