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Solve for the roots in simplest form using the quadratic formula:
2x²+26=20x
PLEASE HELP

asked
User Tavousi
by
8.4k points

1 Answer

6 votes

Answer:


5 + 2√(3)

&


5-2√(3)

Step-by-step explanation:

Okay! The equation is : 2x²+26=20x

Right off the bat we notice that this can be simplified. We divide all numbers by a common multiple: 2.

Our resulting equation is
x^2 + 13= 10x

Now, in order to plug this equation into our quadratic formula, we need to rearrange this equation into the
ax^2 + bx +c = 0 format.

In order to do that, we simply move the 10x to the left side of the equation, resulting in this:
x^2 - 10x + 13

Here is the quadratic formula:

(-b±√(b²-4ac))/ 2a

I will include a picture of the quadratic equation at the bottom (because the typed equation is strange).

So looking at our previously found formula, x^2 - 10x + 13, we know that a: 1

b: -10

c: 13

Now, we plug in our values!

(-(-10) ± √((-10)²-(4(1)(13))) / 2(1)

Simplify! (10 ± √(100-52)) / 2

Simplify again! (10 ± √48) / 2

Now we must simplify the square root. If we try to find the square root of 48, it comes out to 6.92820323, which is a very messy number. We will NOT be using this number. We will instead find the factors of 48.

2·2·2·2·3 = 48

So it looks like this: √2·2·2·2·3

We can pair up the similar numbers, so it looks like: √(2·2)(2·2)·3

Now, we move the pairs of twos to the front of the equation (but only one two from each pair is represented because they've been square-rooted) , and out of the square root, to get us: 2·2 √3, which equals 4√3

Now that we have the square root figured out, we re-enter the square root into the equation we had before (replacing the un-simplified version with the simplified version), which was (10 ± √48) / 2.

Here is the equation with the simplified root: (10 ± 4√3) / 2

Now we notice that 10 and 4 are divisible by 2, so the equation becomes: (5 ± 2√3), which is 5+2√3, AND 5-2√3

Hope that helped!!!!

Solve for the roots in simplest form using the quadratic formula: 2x²+26=20x PLEASE-example-1
answered
User Johann Chang
by
7.5k points

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