76.

Describe two different ways that you could find the product of 8 times 977 using mental math. Find the product and explain why y

Natalka [10]

$8 \times 977 = 8 \times (1000 - 23) = 8000 - 8(23) = 8000 - 8(25-2) = 8000 - 200 + 16 = 7816$

$8 \times 977 = 8 \times (975 + 2) = 16 + 8 \times 900 + 8 \times 75 = 16 + 7200 + 24 \times 25 = 7216 + 600 = 7816$

Why does it work? Mostly the distributive law.

3 0

3 years ago

Will give brainliest and thanks

Maru [420]

Answer:

y = -3x - 3

Step-by-step explanation:

First, determine the slope of the red line. As we move from (0, 3) to (1, 0),

x increases by 1 and y decreases by 3. Hence, the slope, m, is

m = rise / run = -3 / 1, or m = -3.

The desired new line, parallel to the red line, has the same slope as the red line: m = -3.

The equation for this new line is y - k = m (x - h), where (h, k): (-1, 0):

We get y - 0 = -3 (x + 1), or y = -3x - 3.

Check: Does this line go thru the given point (-1, 0)?

Is 0 = -3(-1) - 3 true? Yes, it is true.

6 0

3 years ago

A professor would like to test the hypothesis that the average number of minutes that a student needs to complete a statistics e

professor190 [17]

Answer:

$\chi^2 =\frac{15-1}{25} 16 =8.96$

The degrees of freedom are given by:

$df = n-1 = 15-1=14$

The p value for this case would be given by:

$p_v =P(\chi^2$

Since the p value is higher than the significance level we have enough evidence to FAIL to reject the null hypothesis and we can conclude that the true deviation is not ignificantly lower than 5 minutes

Step-by-step explanation:

Information given

$n=15$ represent the sample size

$\alpha=0.05$ represent the confidence level

$s^2 =16$ represent the sample variance

$\sigma^2_0 =25$ represent the value that we want to verify

System of hypothesis

We want to test if the true deviation for this case is lesss than 5minutes, so the system of hypothesis would be:

Null Hypothesis: $\sigma^2 \geq 25$

Alternative hypothesis: $\sigma^2$

The statistic is given by:

$\chi^2 =\frac{n-1}{\sigma^2_0} s^2$

And replacing we got:

$\chi^2 =\frac{15-1}{25} 16 =8.96$

The degrees of freedom are given by:

$df = n-1 = 15-1=14$

The p value for this case would be given by:

$p_v =P(\chi^2$

Since the p value is higher than the significance level we have enough evidence to FAIL to reject the null hypothesis and we can conclude that the true deviation is not ignificantly lower than 5 minutes

6 0

3 years ago

Rationalize the denominator in each expression. That is, rewrite the expression so that there is a rational expression in the de

ad-work [718]

Answer:

explanations: we multiply with a rational surd

(x-9)*√(x+9)/(√(x-9)*√(x+9)

=(x-9)√(x+9)/

$x {}^{2} - 9$

B.( x-9)/√x+3 =( x-9)*(√x-3)/(√x+3)*(√x-3)

= (x-9)*(√x-3)/x-9

=√x-3

7 0

4 years ago

The number of students at a school who ate in the cafeteria yesterday can be represented by the expression 4/5k where K is the n

Lemur [1.5K]

What are the Expression Choices ?

6 0

3 years ago