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sveta [45]
3 years ago
5

Solve the following quadratic equation5х2 - 10x – 21 = 39​

Mathematics
2 answers:
-BARSIC- [3]3 years ago
3 0

Answer:

x=1+√13 or x=1−√13

Step-by-step explanation:

Step 1: Subtract 39 from both sides.

5x2−10x−21−39=39−39

5x2−10x−60=0

For this equation: a=5, b=-10, c=-60

5x2+−10x+−60=0

Step 2: Use quadratic formula with a=5, b=-10, c=-60.

x=

−b±√b2−4ac

2a

x=

−(−10)±√(−10)2−4(5)(−60)

2(5)

x=

10±√1300

10

x=1+√13 or x=1−√13

ycow [4]3 years ago
3 0

Answer:

Step-by-step explanation:

Rewrite this quadratic in standard form by subtracting 39 from both sides.  We get:

5x^2 - 10x - 60 = 0

Reduce this by dividing all four terms by 5:

x^2 - 2x - 12 = 0

Use the quadratic equation to find the roots.  The coefficients of the x terms are 1, -2, -12. Thus the discriminant is b^2 - 4ac, or:

(-2)^2 - 4(1)(-12)  = -44   of which 4 is a perfect square factor and 11 is not.

Because the discriminant is negative, the given equation has two unequal, complex roots, which are:

      -(-10) ± i√4√11

x = -----------------------

                10

or x = 1 ± (1/5)√11

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All of them plz btw look at my other answer to see to data
torisob [31]
For the first question, you have to subtract the Panther's length from the Crocodile's length. BUT there is a problem with this since you CANNOT subtract two fractions if their denominators are NOT the same.

To fix this issue you have to make them the same, which you can do by finding their "equal denominator". To find the "equal denominator" you have to multiply both fraction's denominators till they both end up the same.

Take the panther's fraction for instance, 1/2.
Multiply 1/2's denominator by 2 and you get 1/4, but, this changes the fraction's meaning, so you have to multiply the numerator by the same number as well, which is 2 in this case.

You should end up with the panther's fraction being 2/4, and just remember, this number means the same thing as 1/2 when simplified.

Both denominators are now the same, so now you can finally subtract both fractions. But you can't subtract denominators, remember that! You should end up with 4 1/4, that is the first answer.

Repeat those steps for the 2nd question.

For number 3, you need to add both fractions together, but in this case, you STILL need both denominators to be the same. So, multiply the fractions until each denominator is the same. And remember, you can't add or subtract denominators, but however, you can multiply and divide them!

You should end up with 4 5/4. BUT this is not the answer! 5/4 is not a fraction in it's simplest form. To simplify, in this case, you would subtract 4 from that 5, and add one to the whole number, 4. Why did we do this?

Think of the denominator (the bottom number in a fraction) as being a whole number for the numerator (the top number in a fraction). Let's say the numerator is a 2 and the denominator a 5. The numerator has 2 pieces of that "whole" (the 5), so when the numerator reaches a 5, you get a WHOLE NUMBER. If the numerator is ABOVE 5, you still get a whole number but you have "excess" left over, that "excess" will become the remaining numerator.

So, your final answer should be, for this question, 5 1/4.

For question number 4 repeat the same steps in questions 1 and 2.

Question 5 is a little more complex than number 3 but it's actually very easy to do, just repeat the steps in question 3.

Question six is the same as number 5.

I hope I helped! If you have any more question don't be afraid to ask! ^u^
5 0
3 years ago
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serg [7]
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8 0
3 years ago
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Alex787 [66]

Answer:

16

Step-by-step explanation:

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6 0
3 years ago
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Answer:
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Explanation:
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7 0
4 years ago
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vodomira [7]

Answer:

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Step-by-step explanation:

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3 years ago
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