Solve the equation by completing the square

Mathematics

1 answer:

Ilya [14]3 years ago

4 0

Answer:

We got the quadratic equation:

$x^2+8x-3=0$

Solving by completing the square:

$x^2+8x-3=0\\x^2+8x+16-16-3=0\\(x+4)^2-16-3=0\\(x+4)^2-19=0\\(x+4)^2=19\\x+4=\pm \sqrt{19} \\x=-4\pm \sqrt{19} \\\\x_{1} =-4+\sqrt{19} \\x_{2} =-4-\sqrt{19}$

Therefore, the answer is letter C

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What assumption should be made to prove this conjecture by contradiction? If it is raining, then I will not go swimming.

Anon25 [30]

Here are some options to make deciding easier-

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B) it is raining
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3 years ago

Samuel can type nearly 40 words per minute. Use this information to find the number of hours it would take him to type 2.9 × 105

AleksAgata [21]

Answer:

Samuel can type 40 words per minute

Step-by-step explanation:.

Then how many hours will it take for him to type 2.6 words times 10 to the power of five words

=> 2.6 words time 10 to the power of 5

=> 2.6 x 10^5

=> 2.6 x 100 000

=> 260 000 words in all.

Now, we need to find the number of words Samuel can type in a hour

=> 40 words / minutes , in 1 hour there are 60 minutes

=> 40 x 60

=> 2 400 words /hour

Now, let’s divide the total of words he need to type to the number of words he can type in an hour

=> 260 000 / 2 400

=> 108.33 hours.

4 0

3 years ago

Find all solutions to the equation.<br><br> 7 sin2x - 14 sin x + 2 = -5

cestrela7 [59]

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