<u><em>Solution:</em></u>
<u><em></em></u>
Hope this helps!
Answer: 
<u>Step-by-step explanation:</u>
Given: cos x =
, x is in Quadrant 4
Use Pythagorean Theorem to find sin x:
8² + y² = 17²
y² = 17² - 8²
y² = 289 - 64
y² = 225
y = 15
→ sin x = 
Use the double angle formula to find cos (2x):

Given:
Choose a number between 0 and 20.
If the difference is less than 10 then Eric wins.
Let us x is Eric's number. 0 <u><</u> x <u><</u> 20
If Eric wins. |x -7| < 10
|x-7| < 10 → -10 < x-7 < 10 → -10 + 7 < x - 7 + 7 < 10 + 7 → -3 < x < 17
Taking into account that the number must be given between 0 and 20.
0 <u><</u> x <u><</u> 20
-3 < x < 17
→ 0 < x < 16
Answer: the answer is 0
Step-by-step explanation:
Answer: -116
Step-by-step explanation: Since negative numbers are involved, the best way to solve this is add 95 and POSITIVE 21. This gives you 116. Since you move from a positive to a negative, the 116 needs to be negative