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Elena-2011 [213]
3 years ago
9

Using the quadratic formula to solve x2 + 20 = 2x, what are the values of x?

Mathematics
1 answer:
telo118 [61]3 years ago
3 0

The values of x are:

1+√19i

1-√19i

Step-by-step explanation:

Given equation is:

x^2+20=2x\\x^2-2x+20=0\\Comparing\ with\ the\ standard\ form\ of\ quadratic\ equation\\ax^2+bx+c = 0\\a=1\\b=-2\\c=20Using Quadratic formula\\x = \frac{-b+\sqrt{b^2-4ac}}{2a}\ \ \ , x = \frac{-b-\sqrt{b^2-4ac}}{2a}\\x = \frac{-(-2)+\sqrt{(-2)^2-4(1)(20)}}{2(1)}\ \ \ , x = \frac{-(-2)-\sqrt{(-2)^2-4(1)(20)}}{2(1)}\\x = \frac{2+\sqrt{4-80)}}{2}\ \ \ , x = \frac{2-\sqrt{4-80)}}{2}\\x = \frac{2+\sqrt{-76)}}{2}\ \ \ , x = \frac{2-\sqrt{-76)}}{2}\\

x = \frac{2+\sqrt{-19*4}}{2}\ \ \ , x = \frac{2-\sqrt{-19*4}}{2}\\x = \frac{2+\sqrt{-19*4}}{2}\ \ \ , x = \frac{2-\sqrt{-19*4}}{2}\\x = \frac{2+2\sqrt{-19}}{2}\ \ \ , x = \frac{2-2\sqrt{-19}}{2}\\x = \frac{2(1+\sqrt{-19})}{2}\ \ \ , x = \frac{2(1-\sqrt{-19})}{2}\\x = 1+\sqrt{-19}\ \ \ , x = 1-\sqrt{-19}\\\sqrt{-19} = \sqrt{19}*\sqrt{-1} \\As\ we\ know => \sqrt{-1} =i\\\sqrt{-19} = \sqrt{19}i\\So,\\x= 1+\sqrt{19}i\ \ \ \ , x=1-\sqrt{19}i

The values of x are:

1+√19i

1-√19i

Keywords: Quadratic equation, value of variable

Learn more about quadratic equation at:

  • brainly.com/question/10364988
  • brainly.com/question/10435816

#LearnwithBrainly

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Black_prince [1.1K]

Answer:

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Step-by-step explanation:

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so there is a total of 10 full sets of keys

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Lostsunrise [7]

To find the time Jack takes to cross Swan Lake, his average speed is required:

The time it will take Jack to cross Swam Lake is <u>0.5 hours</u>

Reason:

Time it took Jack to paddle 6.4 km upstream, t = 2 hours

Distance Jack paddled, d = 6.4 km

The given speed of the Black River, <em>v₂</em> = 1.8 km/h

The width of the lake, w = 2.5 km

The time it will take Jack to cross Swan Lake

Let <em>v₁</em>, represents Jack's speed, we have;

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Therefore;

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  • Jack's speed, v₁ = 5 km/h

Time \ to \ cross \  the \ lake , \ t_S = \dfrac{w}{v_1}

t_S = \dfrac{2.5 \, km}{5 \, km/h}  = 0.5 \, hr.

The time it will take Jack to cross Swan Lake, t_S = <u>0.5 hours</u>

Learn more here:

brainly.com/question/17168275

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