(-7/8)(-3/4) A:6/7 B:-21/32 C:21/32

Anyone know this one?

SSSSS [86.1K]

Answer is a because a^-2 will be changed to 1/a^2

Hope that helps

5 0

3 years ago

Graph this function using intercepts: 4x - 5y = 40

DochEvi [55]

use photomath for that that's way easier

4 0

2 years ago

Read 2 more answers

When a constant force acts upon an object, the acceleration of the object varies inversely with its mass. When a certain constan

vitfil [10]

Answer:

$a = 6m/s^2$

Step-by-step explanation:

Given

When mass = 4kg; Acceleration = 15m/s²

Required

Determine the acceleration when mass = 10kg, provided force is constant;

Represent mass with m and acceleration with a

The question says there's an inverse variation between acceleration and mass; This is represented as thus;

$a\ \alpha\ \frac{1}{m}$

Convert variation to equality

$a = \frac{F}{m}$ ; Where F is the constant of variation (Force)

Make F the subject of formula;

$F = ma$

When mass = 4kg; Acceleration = 15m/s²

$F = 4 * 15$

$F = 60N$

When mass = 10kg; Substitute 60 for Force

$F = ma$

$60 = 10 * a$

$60 = 10a$

Divide both sides by 10

$\frac{60}{10} = \frac{10a}{10}$

$a = 6m/s^2$

Hence, the acceleration is  $a = 6m/s^2$ 

4 0

2 years ago

A random sample of n = 40 observations from a quantitative population produced a mean x = 2.2 and a standard deviation s = 0.29.

zmey [24]

Answer:

$t=\frac{2.2-2.1}{\frac{0.29}{\sqrt{40}}}=2.18$

$df=n-1=40-1=39$

Since is a one side test the p value would be:

$p_v =P(t_{(39)}>2.18)=0.0177$

If we compare the p value and the significance level given $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and then the population mes seems to be higher than 2.1 at 5% of significance

Step-by-step explanation:

Data given and notation

$\bar X=2.2$ represent the sample mean

$s=0.29$ represent the sample standard deviation

$n=40$ sample size

$\mu_o =2.1$ represent the value that we want to test

$\alpha=0.05$ represent the significance level for the hypothesis test.

t would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the mean is higher than 2,1, the system of hypothesis would be:

Null hypothesis: $\mu \leq 2.1$

Alternative hypothesis: $\mu > 2.1$

If we analyze the size for the sample is > 30 but we don't know the population deviation so is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:

$t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (1)

t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Calculate the statistic

We can replace in formula (1) the info given like this:

$t=\frac{2.2-2.1}{\frac{0.29}{\sqrt{40}}}=2.18$

P-value

The first step is calculate the degrees of freedom, on this case:

$df=n-1=40-1=39$

Since is a one side test the p value would be:

$p_v =P(t_{(39)}>2.18)=0.0177$

Conclusion

If we compare the p value and the significance level given $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and then the population mes seems to be higher than 2.1 at 5% of significance

7 0

3 years ago

Find the product.

4vir4ik [10]

Answer :

$6{y}^{4} {z}^{2} + 12 {y}^{3} {z}^{2}-3 {y}^{3} {z}+3 {y}^{2} {z}^{2}$

Step-by-step explanation :

To find the product of

$3 {y}^{2} z(2 {y}^{2} z + 4yz - y + z)$

First we expand the bracket ,

it implies that, we use the expression outside the bracket to multiply individual expressions inside the bracket.

Hence

$3 {y}^{2} z(2 {y}^{2} z + 4yz - y + z)$

$= 3 {y}^{2} z(2 {y}^{2} z) + 3 {y}^{2} z(4yz) - 3 {y}^{2} z(y )+3 {y}^{2} z( z)$

we now apply the law of indices

${a}^{m} \times {a}^{n} = {a}^{m+n}$

meaning, when you are multiplying two expressions with the same bases , repeat one of the bases and add the exponents.

Then, simplify to obtain

$= 6{y}^{4} {z}^{2} + 12 {y}^{3} {z}^{2}-3{y}^{3} {z}+3 {y}^{2} {z}^{2}$

3 0

2 years ago

(-7/8)(-3/4)A:6/7B:-21/32C:21/32