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jolli1 [7]
3 years ago
13

Use quadratic formula solve .7x^2 - 28x - 7​

Mathematics
1 answer:
beks73 [17]3 years ago
6 0

Answer:

x = 2 + sqrt(5) or x = 2 - sqrt(5)

Step-by-step explanation using the quadratic formula:

Solve for x over the real numbers:

7 (x^2 - 4 x - 1) = 0

Divide both sides by 7:

x^2 - 4 x - 1 = 0

Add 1 to both sides:

x^2 - 4 x = 1

Add 4 to both sides:

x^2 - 4 x + 4 = 5

Write the left hand side as a square:

(x - 2)^2 = 5

Take the square root of both sides:

x - 2 = sqrt(5) or x - 2 = -sqrt(5)

Add 2 to both sides:

x = 2 + sqrt(5) or x - 2 = -sqrt(5)

Add 2 to both sides:

Answer:  x = 2 + sqrt(5) or x = 2 - sqrt(5)

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A sample of students that had stuffy or runny noses were blindly given a single Skittles candy to put in their mouth. They were
Korvikt [17]

Answer:

The confidence interval is  0.2857<  p <  0.4601

Step-by-step explanation:

From the question we are told that

  The sample size is  n  =  118  

   The  number that gave the correct answer is  k =  44

Generally the sample proportion is mathematically represented as

      \^ p = \frac{44}{118}

=>     \^ p =0.3729

Generally given that the confidence level is  95% the level of significance is mathematically represented as

       \alpha  =  (100 -95) \%

=>     \alpha = 0.05

Generally from the normal distribution table the critical value  of  \frac{\alpha }{2} is  

   Z_{\frac{\alpha }{2} } =  1.96

Generally the margin of error is mathematically represented as  

     E =  Z_{\frac{\alpha }{2} } * \sqrt{\frac{p(1 - p)}{n} }

=>   E =  1.96 * \sqrt{\frac{0.3729(1 - 0.3729)}{118} }

=>    E = 0.0872

Generally 95% confidence interval is mathematically represented as  

             \r p -E <  p <  \r p +E

=>    0.3729 -0.0872<  p <  0.3729 +0.0872

=>  0.2857<  p <  0.4601

5 0
3 years ago
Which expression is equivalent to ?
mamaluj [8]

Answer:

Step-by-step explanation:

\frac{(a^{2}b^{4}c)^{2}*(6a^{3}b)*(2c^{5})^{3}}{4a^{6}b^{12}c{^3}}\\\\=\frac{a^{2*2}b^{4*2}c^{2}6a^{3}b2^{3}c^{5*3}}{4a^{6}b^{12}c{^3}}\\\\=\frac{a^{4}b^{8}c^{2}6a^{3}b8c^{15}}{4a^{6}b^{12}c{^3}}\\\\=\frac{6*8*a^{4+3}b^{8+1}c^{2+15}}{4a^{6}b^{12}c{^3}}\\\\=\frac{6*2*a^{7}b^{9}c^{17}}{a^{6}b^{12}c{^3}}\\\\=\frac{12a^{7-6}c{17-3}}{b^{12-9}}\\\\=\frac{12a^{1}c^{14}}{b^{3}}\\\\=\frac{12ac^{14}}{b^{3}}

Hint:

x^{m}*x^{n}=x^{m+n}\\\frac{x^{m}}{x^{n}}=x^{m-n},m>n\\\frac{x^{m}}{x^{n}}=\frac{1}{x^{n-m}},n>m

5 0
3 years ago
In ANOVA analyses, when the null hypothesis is rejected, we can test for differences between treatment means by ________. Group
nikklg [1K]

Answer:

When conducting an analysis of variance analysis on a set of samples and the null hypothesis is rejected, we can test for the difference between treatment can be tested with the aid of a t-test. This is employed when 2 related groups are involved. Independent sample, paired sample or one-sample t-test can be conducted.

Step-by-step explanation:

A t-test is a test statistic used to make inferences that determine the differences that exist statistically between 2 related groups. It tells us if the 2 groups tested are from the same population. There are 3 types of t-test namely independent sample t-test, paired-sample t-test and one-sample t-test

5 0
3 years ago
Students at Hampton Middle School sold T-shirts as a school fundraiser. Sylvie asked 12 random seventh-grade students how many T
AveGali [126]

Answer:

b. 4.1 shirts

Step-by-step explanation:

Given data:

number of terms = 12

Terms given are 3, 4, 8, 5, 2, 5, 0, 5, 3, 4, 3, 7

Mean = (sum of terms)/ (number of terms)

Mean = (3 +4+ 8+ 5+2+5+0+ 5+ 3+ 4+3+ 7)/12

Mean = 49/12

Mean = 4.083

Mean = 4.1 (<em>to the nearest tenth)</em>

7 0
3 years ago
Read 2 more answers
Given the graph of the function f below, estimate the intervals in which fis<br> increasing.
nadezda [96]

Answer:

  (-∞, -5/2) ∪ (1, ∞)

Step-by-step explanation:

"Increasing" means the graph goes up to the right. It is increasing from the left up to the local maximum--the peak at left.

It is increasing again from the local minimum on the right to the right side of the graph.

The two sections where the graph is increasing are ...

  (-∞, -5/2) ∪ (1, ∞)

__

The graph is <em>decreasing</em> between the maximum on the left and the minimum on the right.

6 0
3 years ago
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