Answer is the last choice
2a-4/1= -a-1/a-4
Cross multiply
(2a-4)(a-4)= -(a-1)
2a^2-8a-4a+16= -a+1
Bring right to left sign change signs
2a^2-8a-4a+16+a-1=0
Combine like terms
2a^2-11a+15=0
a= 2 b= -11 c= 15
Use quadratic formula
-b+-sq rt of b^2-4ac. Divided by 2a
-(-11) +- 11^2-4(2)(15) divided by 2(2)
11+-sq rt 121-120 divided by 4
11+1 /4. 11-1/4
12/4. 10/4
3. , 5/2
Cos(pi) = -1
You should have this memorized along with other values such as
sin(0) = 0
cos(0) = 1
sin(pi/2) = 1
cos(pi/2) = 0
sin(pi) = 0
cos(pi) = -1
sin(3pi/2) = -1
cos(3pi/2) = 0
and remember that tan = sin/cos
Im pretty sure the answer is 7.84. i got this because 7 is a whole number so it is in the whole number spot. Then, you have to get your denominator to 100. So, what times 25 equals 100? its 4. so you get 100 so whatever you do to your denominator you do to your numerator. so 21 times 4 is 84. so 84/100 is actually 7.84. Hope this helped
If you write

, you'll notice this is really just a quadratic equation that can be factorized:

So you have

and
Answer: Angles who share the same initial side and terminal sides.