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3 years ago

C) Write the equation in factored form. The equation is y= x^2 - 8x - 20 // Need answer ASAP

Mathematics

1 answer:

netineya [11]3 years ago

8 0

The first term will be an x because

x squared breaks down as x times x.

First look for factors of your constant that add to your

coefficient of the middle term in the trinomial.

Also note that the constant is negative and a negative

factors as the product of a positive and a negative.

The factors of -20 that add to -8 are -10 and +2.

So we have y = (x - 10)(x + 2).

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5) Assume this is an acceleration graph, where the X axis represents time in seconds and the Y axis represent velocity in m/s. W

Stels [109]

Answer:

D) Acceleration is positive and increasing.

Step-by-step explanation:

In formulae, acceleration is defined as the rate of change of velocity per unit time; for example:

$a=\frac{v}{t}$

where Δ V is the variation of velocity and Δ T is the variation in time.

The graph depicts the velocity of a moving item as a function of time. As we can see ΔV is the increment on the y-axis, while ΔT is the increment on the x axis: therefore, the ratio ΔV/ΔT is the curve's slope. In fact, the slope of the curve in a velocity-time graph corresponds to the object's acceleration. In this graph, we can see that the slope of the curve is growing, which means that the acceleration is positive (since the slope is positive and the velocity is increasing) and increasing (because the slope is increasing).

6 0

3 years ago

Mario claims that if the dinominator of a fraction is a prime number, then its decimal form is a repeting decimal. Do you agree?

vodomira [7]

Answer:

I do not agree because Mario's claim is not general.

Step-by-step explanation:

Prime numbers: These are a set of numbers that are divisible by 1 and itself only. Examples are: 2, 3, 5, 7. 11 etc.

And a denominator is the divisor in a given fraction.

Considering the following fractions whose denominators are prime numbers:

$\frac{2}{3}$ = 0.66666666...

$\frac{1}{7}$ = 0.142857142

$\frac{5}{11}$ = 0.45454545...

$\frac{3}{13}$ = 0.23076923

$\frac{1}{7}$ = 0.142857142

It could be observed that Mario's claim is not a general principle which is applicable to all fractions with a prime denominator. Thus, I do not agree with his claim.

4 0

3 years ago

Scores on the SAT Mathematics test are believed to be normally distributed. The scores of a simple random sample of five student

AysviL [449]

Answer:

The mean calculated for this case is $\bar X=584$

And the 95% confidence interval is given by:

$584-2.776\frac{86.776}{\sqrt{5}}=476.271$

$584+2.776\frac{86.776}{\sqrt{5}}=691.729$

So on this case the 95% confidence interval would be given by (476.271;691.729)

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

s represent the sample standard deviation

n represent the sample size

Solution to the problem

The confidence interval for the mean is given by the following formula:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

In order to calculate the mean and the sample deviation we can use the following formulas:

$\bar X= \sum_{i=1}^n \frac{x_i}{n}$ (2)

$s=\sqrt{\frac{\sum_{i=1}^n (x_i-\bar X)}{n-1}}$ (3)

The mean calculated for this case is $\bar X=584$

The sample deviation calculated $s=86.776$

In order to calculate the critical value $t_{\alpha/2}$ we need to find first the degrees of freedom, given by:

$df=n-1=5-1=4$

Since the Confidence is 0.95 or 95%, the value of $\alpha=0.05$ and $\alpha/2 =0.025$ , and we can use excel, a calculator or a tabel to find the critical value. The excel command would be: "=-T.INV(0.025,4)".And we see that $t_{\alpha/2}=2.776$