80-30=50 your answer would be 50
Answer:
10
Step-by-step explanation:
The answer is 10 because there are 20 days and no home work is due on 7 of those days so that’s 13 days with homework from math or writing. Then you take the three days where it was just math and subtract that to get 10 days of writing.
Use the 30-60-90 triangle.
Tan is opposite over adjacent.

Square roots cannot be on the bottom.

The bottom cancel out the square root bar.
Your answer is:

(It's best to memorize the 30-60-90 and the 45-45-90 triangles during trigonometry. It helps a lot.)
Hope this helps!
:)