Answer: 140
Step-by-step explanation: 25x20=500
32x20=640
640-500= 140!!
The correct question is
<span>
Penelope determined the solutions of the quadratic function by completing the square.f(x) = 4x² + 8x + 1
–1 = 4x² + 8x
–1 = 4(x² + 2x)
–1 + 1 = 4(x² + 2x + 1)
0 = 4(x + 2)²
0 = (x + 2)²
0 = x + 2
–2 = x
What error did Penelope make in her work?
we have that
</span>f(x) = 4x² + 8x + 1
to find the solutions of the quadratic function
let
f(x)=0
4x² + 8x + 1=0
Group terms that contain the same variable, and move the
constant to the opposite side of the equation
(4x² + 8x)=-1
Factor the
leading coefficient
4*(x² + 2x)=-1
Complete the square Remember to balance the equation
by adding the same constants to each side.
4*(x² + 2x+1)=-1+4 --------> ( added 4 to both sides)
Rewrite as perfect squares
4*(x+1)²=3
(x+1)²=3/4--------> (+/-)[x+1]=√3/2
(+)[x+1]=√3/2---> x1=(√3/2)-1----> x1=(√3-2)/2
(-)[x+1]=√3/2----> x2=(-2-√3)/2
therefore
the answer is
<span>
Penelope should have added 4 to both sides instead of adding 1.</span>
We are given function: y= 
Where, x is the number of hours after 5a.m.
We need to approximates the number of people standing in line to catch a commuter train at 7 a.m.
From 5 a.m. to 7 a.m. total number of hours = 7-5 = 2 hours.
So, we need to plug x=2 in the given function.
Plugging x=2 in 
, we get
Let us simplify it now.
2^2= 4.
Therefore,
= -20.524 + 63.642 - 3.333.
= 39.785 or 40 approximately.
Therefore, the number of people in line at 7 a.m. is approximately 40 people.
Option D.40 is correct option.
I think its d. Because it is to the nearest thousands. And you cannot find the long sides of the rectangle,because you need another one info. about the number of the long sides or the perimeter or the area. Im happy if i helped you
Answer: f(-6) = 
, f(-4) = 
, f(4) = 
, f(6) = 
<u>Step-by-step explanation:</u>
(-6, f(-6)) is an x,y coordinate. They are asking what the y-value is when you plug in -6 for x.
f(x) = 
f(-6) = 
= 
=
f(-4) = 
= 
= 
=
f(4) = 
= 
= 
=
f(6) = 
= 
=
