The answer is 10% because 10% of 40 is 4
Let oil change be x
91 / 7 = x / 11
(91 * 11) / 7 = x
13 * 11 = x
<span>143 = x Ans</span>
Answer:
28
Step-by-step explanation:
Answer:
See the proof below
Step-by-step explanation:
For this case we need to proof the following identity:

We need to begin with the definition of tangent:

So we can replace into our formula and we got:
(1)
We have the following identities useful for this case:


If we apply the identities into our equation (1) we got:
(2)
Now we can divide the numerator and denominato from expression (2) by
and we got this:

And simplifying we got:

And this identity is satisfied for all:
