B = 12 - a
Subtract a from both sides to isolate b, and you get the answer.
Answer:
Jml for number one because if you flip the top triangle over you have two like triangles just not the same size but angles are the same
Number 25 edc because of the same reason
Step-by-step explanation:
Answer:
X=2
Step-by-step explanation:
Looks more like Trig than Algebra II
They want us to apply the sum angle formula to 
5π/6 is 150°; I find it easier to think in degrees.
When the tangent of x is 3/4 that's a right triangle with opposite 3, adjacent 4 so hypotenuse 5. So a sine of 3/5 and a cosine of 4/5, both positive because we're told x is in the first quadrant.
The sine sum angle formula is


We know sin 150° = sin 30° = 1/2 and cos 150° = - cos 30° = -√3/2


Third choice