Given:
The power generated by an electrical circuit (in watts) as a function of its current x (in amperes) is modeled by

To find:
The current which will produce the maximum power.
Solution:
We have,


Differentiate with respect to x.

...(i)
To find the extreme point equate P'(x)=0.


Divide both sides by -30.

Differentiate (i) with respect to x.

(Maximum)
It means, the given function is maximum at x=4.
Therefore, the current of 4 amperes will produce the maximum power.
Answer:
9x -45
Step-by-step explanation:
The distributive property tells you the factor outside parentheses applies to each of the terms inside parentheses:
-9(-x +5) = (-9)(-x) +(-9)(5)
= 9x -45
The total measure of all the angles in a triangle is 180°.
Since there is already a 90° angle, the other 2 angles must also add up to 90°.
The only answer that fits is x = 9.
Check:
9x7 = 63°
3x9 = 27°
Add up = 90°
:)
16 is the answer to this question.