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Gnesinka [82]
3 years ago
15

Find the value of k byquardractic equation two real and equal roots5x - 2kx +20=0​

Mathematics
2 answers:
ki77a [65]3 years ago
7 0

Step-by-step explanation:

Given Equation

5x-2kx+20=0

  • If it has real and equal roots then

\boxed{\sf \longrightarrow D=0 }

  • Substitute the values

\\\qquad\quad\displaystyle\sf {:}\longrightarrow b^2-4ac=0

\\\qquad\quad\displaystyle\sf {:}\longrightarrow (-2k)^2-4\times 5\times 20=0

\\\qquad\quad\displaystyle\sf {:}\longrightarrow 4k^2-20\times 20=0

\\\qquad\quad\displaystyle\sf {:}\longrightarrow 4k^2-400=0

\\\qquad\quad\displaystyle\sf {:}\longrightarrow 4k^2=400

\\\qquad\quad\displaystyle\sf {:}\longrightarrow k^2=\dfrac {400}{4}

\\\qquad\quad\displaystyle\sf {:}\longrightarrow k^2=100

\\\qquad\quad\displaystyle\sf {:}\longrightarrow k=\sqrt{100}

\\\qquad\quad\displaystyle\sf {:}\longrightarrow k=10

\therefore\sf k=10

kotegsom [21]3 years ago
3 0

Answer:

k = +10 or -10

Step-by-step explanation:

It's given in the question that the roots of the eqn. are real and equal. So , the discriminant of the eqn. should be equal to 0.

=  >  {b}^{2}  - 4ac = 0

=  >  {( - 2k)}^{2}  - 4 \times 5 \times 20 = 0

=  > 4 {k}^{2}  - 400 = 0

=  > 4( {k}^{2}  - 100) = 0

=  >  {k}^{2}  - 100 = 0

=  > k =  \sqrt{100}  =  + 10 \: or \:  - 10

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frez [133]

Answer: B

Step-by-step explanation:

A factorial is multiplying the integer and all of the integers below it together.

3 0
3 years ago
Can someone please help me
Readme [11.4K]
Surface Area of the figure is 1208 square centimeters
a=20
b=13
c=12
d=5
e=8
Top face:
A1=a×e=20×8
ae=160
Bottom face:
A2(a+2d)×e=(20+2×5)×8=(20+10)×8=30×8
(a+2d)e=240
Front face:
Rectangle
a×c=20×12=240
Triangle:
12c×d=12×12×5=6×5=30
A3Rectangle +2 triangles
240+2×30=240+60=300
(a+d)c=300
Slant face:
A4=b×e=13×8=104
be=104
Total surface area
A=A1+A2+2(A3+A4)
A1=160
A2=240
A3=300
A4=104
Thus,
A=160+240+2(300+104)
A=400+2(404)
A=400+808=1208
Surface Area of the figure is 1208 square centimeters


8 0
3 years ago
(07.05)<br> Graph the first six terms of a sequence where a = -10 and d = 3.
butalik [34]

Answer:

15

Step-by-step explanation:

Using the formular, Sn = n/2(2a + (n - 1)d)

where, n = 6: Sn = 6/2( -20 + 5(3)) = 3(15 - 20)

∴  Sn = 15

7 0
3 years ago
Assume Cylinder A and Cone B are the same height and the bases have the same radius. If A has a volume of 18π cm3, what is the v
disa [49]

Answer:

Option A  V_B=19\ cm^3

Step-by-step explanation:

The volume of a cone is:

V_B = \pi\frac{hr ^ 2}{3}

The volume of a cylinder is:

V_A = \pi(r ^ 2)h

Both figures have the same height h and the same radius r.

The volume of the cylinderV_A = 18\pi\ cm ^ 3

We want to find the volume of the cone.

Then, we find r and h:

V_A = 18\pi = \pi(r ^ 2)h

We simplify.

V_A = 18 = (r ^ 2)h

Then the product of (r ^ 2)h = 18.

We substitute this in the cone formula and get:

V_B =\frac{\pi}{3}(18)\\\\V_B = \frac{18}{3}\pi\\\\V_B=19\ cm^3

8 0
3 years ago
Read 2 more answers
What is the slope of the line passing through the points (-3, 4) and (2, - 1)?
dimaraw [331]

Answer:

slope = -1 or -x

Step-by-step explanation:

Do y2-y1/x2-x1

Plug in

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If you want to find the equation use one of the points you have.

4 = -1(-3) + b

4 = 3 + b (subtract 3 on each side)

1 = b

y = -1x + 1 is the equation

6 0
3 years ago
Read 2 more answers
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