Not sure how to answer question 4

Option D is correct

Step-by-step explanation:

Applying the cosine theorem for triangle ABC, you would have:

cos (angle BAC) = (BA^2 + CA^2 - BC^2)/(2*BA*CA)

                           = (10^2 + 18^2 - 20^2)/(2*10*18)

                           = 24/360

=> angle BAC = ~86 deg

Hope this helps!

the answer is c

hope this !

f(x) = - 2/3x + 5; f(5/2)

substitute 5/2 in for x:

f(5/2) = -2/3(5/2) + 5

simplify the right side:

f(5/2) = -5/3 + 5

f(5/2) = 10/3

answer:

f(5/2) = 10/3

i hope this you!