I believe it is -7 but I may be misunderstanding the question
Step-by-step explanation:
The ratio cosine tell us that
- In a right angled triangle, the cosine of an angle is the side adjacent to the angle divided by the hypotenuse of the triangle.
In other words,
The side adjacent to angle a is 9. The hypotenuse is 41.
So
This is a sum and difference problem, with the equations
R-N=35
R+N=635
The solution of which is
R=(635+35)/2=335
N=(635-35)/2=300
In general, the sum and difference problem can be solved (most of the time mentally) using
Larger number = (sum + difference)/2
Smaller number = (sum - difference)/2
Remember that you can do anything ot an equaiton as long as you do it to both sides
-8+x=0
add 8 to both sides
8-8+x=0+8
0+x=8
x=8
answer is B. 8
