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>
Well first find the slope of the point
y=mx+b y=-1x+3
slope = -1
then put the problem in point slope form y - y1 = m (x-x1)
y + 3 = -1 (x+1) then solve for y=mx+b again
so y> 2x + 6 is the answer
13.) A=9cm^2
If the area is l•h, and there are 9 cubic squares, that means that the length of each side on the square is 3cm, each square on it equals 1cm.
14.) V=27cm^3
If the volume is l•w•h, then we find the third power square root of 27, so 3•3=9•3=27, the answer is 3cm for the length, width, and height.
15.) V=4,913cm^3
If volume is l•w•h, then what number when raised to the third power equals 4913? The answer is 17, since 17•17=289•17=4913. So the length is 17cm
16.)V=216cm^3
If volume is l•w•h, then what number when raised to the third power equals 216? The answer is 6, since 6•6=36•6=216.
17.)A=121
Is area is l•w, then what number raised to the second power equals 121? The answer is 11, since 11•11=121. Therefore it WILL NOT fit a car with a length of 13ft.
18.)A=141
If area is l•w, then what number raised to the second power equals 141? The answer is 12, since 11.87•11.87=141 (answer was rounded to nearest whole number) meaning that she will need 12ft of fence to enclose her garden.
Area of a triangle = 1/2 x base x height
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Find Height :
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3.75 = 1/2 x 2.5 x height
3.75 = 1.25 x height
height = 3.75 ÷ 1.25
height = 3 meters
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Answer: The height is 3 meters.
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D=answer i think
If im wrong im really sorry!
