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3 years ago

Jacki evaluated the expression below.

Mathematics

2 answers:

lbvjy [14]3 years ago

7 0

Answer:

C Jack did not subtract 12 from 8 correctly

Step-by-step explanation:

$2^3(3-1)+4(8-12)=2^3(2)+4(-4)$

it should be -4, not +4

Minchanka [31]3 years ago

5 0

Jackie didn’t subtract 12 from 8 right, I think

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Solve for x: 2x + 30 = (30/10) * 5(2x + 3) + 87

Svetllana [295]

Answer:
x = -9.375
im not sure if i interpreted the times symbol right

step-by-step explanation:
2x + 30 = (30/10) • 5(2x + 3) + 87
2x + 30 = 3 • 10x + 15 + 87
2x + 30 = 105 • 10x
-2x -2x
30 = 105 • 8x
-105 -105
-75 = 8x
/8 /8
-9.375 = x ?

4 0

3 years ago

Read 2 more answers

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yulyashka [42]

Answer:

hello,

Step-by-step explanation:

$cos(3\theta)+cos(4\theta)\\\\=2*cos(\dfrac{4\theta+3\theta}{2} )*cos(\dfrac{4\theta-3\theta}{2} )\\\\\boxed{=2*cos(\dfrac{7\theta}{2} )*cos(\dfrac{\theta}{2} )}$

6 0

3 years ago

Can somone pls help me .. i will mark u brainliest !

frutty [35]

Answer:

1. D

2. A

3. B

Step-by-step explanation:

1. Add exponents

2. Multiply exponents to outside exponent and to the 16

3. Distribute exponents

6 0

3 years ago

Suppose 462 of 500 randomly selected college students said they would be embarrassed to truthfully admit they could not read at

ANEK [815]

Answer:

We conclude that there is a significant difference in the proportion of all college students who would be embarrassed by these two admissions.

Step-by-step explanation:

We are given that 462 of 500 randomly selected college students said they would be embarrassed to truthfully admit they could not read at a fourth grade level.

Further suppose 135 of 500 randomly selected college students said they would be embarrassed to truthfully admit they could not "do math" at a fourth grade level (like fractions).

Let $p_1$ = proportion of college students who would be embarrassed to truthfully admit they could not read at a fourth grade level.

$p_2$ = proportion of college students who would be embarrassed to truthfully admit they could not "do math" at a fourth grade level.

So, Null Hypothesis, $H_0$ : $p_1-p_2$ = 0 or $p_1= p_2$ {means that there is not any significant difference in the proportion of all college students who would be embarrassed by these two admissions}

Alternate Hypothesis, $H_A$ : $p_1-p_2$ $\neq$ 0 or $p_1\neq p_2$ {means that there is a significant difference in the proportion of all college students who would be embarrassed by these two admissions}

The test statistics that would be used here Two-sample z proportion statistics;

T.S. = $\frac{(\hat p_1-\hat p_2)-(p_1-p_2)}{\sqrt{\frac{\hat p_1(1-\hat p_1)}{n_1}+\frac{\hat p_2(1-\hat p_2)}{n_2} } }$ ~ N(0,1)

where, $\hat p_1$ = sample proportion of college students who would be embarrassed to admit they could not read at a fourth grade level = $\frac{462}{500}$ = 0.924

$\hat p_2$ = sample proportion of college students who would be embarrassed to admit they could not "do math" at a fourth grade level = $\frac{135}{500}$ = 0.27

$n_1$ = sample of college students = 500

$n_2$ = sample of college students = 500

So, test statistics = $\frac{(0.924-0.27)-(0)}{\sqrt{\frac{0.924(1-0.924)}{500}+\frac{0.27(1-0.27)}{500} } }$

= 28.28

The value of z test statistics is 28.28.

Also, P-value of the test statistics is given by;

P-value = P(Z > 28.28) = Less than 0.0005%

Now, at 0.10 significance level the z table gives critical values of -1.645 and 1.645 for two-tailed test.

Since our test statistics doesn't lie within the range of critical values of z, so we have sufficient evidence to reject our null hypothesis as it will fall in the rejection region due to which we reject our null hypothesis.

Therefore, we conclude that there is a significant difference in the proportion of all college students who would be embarrassed by these two admissions.

5 0

4 years ago

11. Find the area of the given figure?

adoni [48]

Answer:

9.62 cm²

Step-by-step explanation:

<h2>Area of sector</h2>

diameter = 7 cm

r = 7 ÷2 = 3.5 cm

Ф = 45°

$\sf \boxed{\text{\bf Area of sector = $\dfrac{\theta}{360}*\pi r^2$}}$