The 2 angles are complemantary or form right angles so
so
. Plugging that into BDC we get 11
In order to find this out, we just needed to find out which one has the same smallest fraction
25 / 35. Divided this by 5 and we will get 5/7 >>> smallest fraction
15/21 . Divided this by 3 and we also will get 5/7 >> smallest fraction
So the answer would be : B. 15/21
hope this helps
Second one...................
Answer: -31
<u>Step-by-step explanation:</u>
f(x) = -x⁴ + 3x³ + x² - 8x - 16
f(3) = -(3)⁴ + 3(3)³ + (3)² - 8(3) - 16
= -81 + 81 + 9 - 24 - 16
= -31