Answer:

Step-by-step explanation:
its
, so you reduce it by 8.
Answer:
None
Step-by-step explanation:
If Angles B and D were equal, then:
AB // CD
And
BC // AD
Since we don't have any such information, we can not call any of them parallel
Answer:
3 + 3.75x=18
subtract 3 from both sides
3.75x=15
divide by 3.75 on both sides
x=4
Step-by-step explanation:
Erotically angles are opposite each other and equal the same degree.
In the image 5x and 120 are vertical angles so 5x needs to equal 120.
X = 120/5
X = 24
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