Answer:
10x + 12 and 6x² + 11x - 7
Step-by-step explanation:
The perimeter (P) of a rectangle is calculated as
P = 2l + 2w ( l is length and w is width )
= 2(2x - 1) + 2(3x + 7) ← distribute parenthesis
= 4x - 2 + 6x + 14 ← collect like terms
= 10x + 12
--------------------------------------------------
The area (A) of a rectangle is calculated as
A = lw
= (2x - 1)(3x + 7) ← expand using FOIL
= 6x² + 14x - 3x - 7 ← collect like terms
= 6x² + 11x - 7
(d) The particle moves in the positive direction when its velocity has a positive sign. You know the particle is at rest when
and
, and because the velocity function is continuous, you need only check the sign of
for values on the intervals (0, 3) and (3, 6).
We have, for instance
and
, which means the particle is moving the positive direction for
, or the interval (3, 6).
(e) The total distance traveled is obtained by integrating the absolute value of the velocity function over the given interval:

which follows from the definition of absolute value. In particular, if
is negative, then
.
The total distance traveled is then 4 ft.
(g) Acceleration is the rate of change of velocity, so
is the derivative of
:

Compute the acceleration at
seconds:

(In case you need to know, for part (i), the particle is speeding up when the acceleration is positive. So this is done the same way as part (d).)
Simplified answer would be 60k^2+k
and you get that answer by combining like terms, Good Luck!
Answer:
<em><u>A.10000</u></em>
<em><u>B.25 more trees must be planted</u></em>
Step-by-step explanation:
⇒Given:
- The intial average yield per acre
= 150
- The initial number of trees per acre
= 100
- For each additional tree over 100, the average yield per tree decreases by 1 i.e , if the number trees become 101 , the avg yield becomes 149.
- Total yield = (number of trees per acre)
(average yield per acre)
<em>A.</em>
⇒If the total trees per acre is doubled , which means :
total number of trees per acre
=
= 200
the yield will decrease by :
- 

⇒total yield = 
<em>B.</em>
⇒to maximize the yield ,
let's take the number of trees per acre to be 100+y ;
and thus the average yield per acre = 150 - y;
total yield = 
this is a quadratic equation. this can be rewritten as ,
⇒ 
In this equation , the total yield becomes maximum when y=25;
<u><em>⇒Thus the total number of trees per acre = 100+25 =125;</em></u>
Simplify the radical by breaking up the radicand into a product of known factors.
