Answer:
Step-by-step explanation:
If the engine torque y (in foot-pounds) of one model of car is given by y=−3.75x^2+23.2x+38.8
The engine speed is at maximum if dy/dx = 0
dy/dx = -2(3.75)x+23.2
dy/dx = -7.5x + 23.2
since dy/dx = 0
0 = -7.5x + 23.2
7.5x = 23.2
x = 23.2/7.5
x = 3.093
Hence the maximum torque is 3.09 rev/min
Answer:
Ali´s secret number is 13
Step-by-step explanation:
Answer:
it is dan
Step-by-step explanation:
because 4/5 is the closest to 1.
The solution is 
<em><u>Solution:</u></em>
Let us assume,

<em><u>Given system of equations are:</u></em>


<em><u>Rewrite the equation using "a" and "b"</u></em>
2a - 3b = -5 ------------ eqn 1
4a + 6b = 14 -------------- eqn 2
<em><u>Let us solve eqn 1 and eqn 2</u></em>
<em><u>Multiply eqn 1 by 2</u></em>
2(2a - 3b = -5)
4a - 6b = -10 ------------- eqn 3
<em><u>Add eqn 2 and eqn 3</u></em>
4a + 6b = 14
4a - 6b = -10
( - ) --------------------
8a = 4

Substitute a = 1/2 in eqn 1

Now let us go back to our assumed values
Substitute a = 1/2 in assumed values

Substitute b = 2 in assumed value

Thus the solution is 
Your answer is C :) blessings