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3 years ago

Someone help me with my algebra homework please

Mathematics

2 answers:

Alla [95]3 years ago

7 0

Answer:

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right

Equality Properties

Multiplication Property of Equality
Division Property of Equality
Addition Property of Equality
Subtraction Property of Equality

Step-by-step explanation:

Step 1: Define

Identify

5a - 10b = 45

b = 3

Step 2: Solve for a

Substitute in b [Equation]: 5a - 10(3) = 45
Multiply: 5a - 30 = 45
[Addition Property of Equality] Add 30 on both sides: 5a = 75
[Division Property of Equality] Divide 5 on both sides: a = 15

EastWind [94]3 years ago

6 0

Answer:

a=3

Step-by-step explanation:

5a-10b=45

when b=3

5a-10×3=45

5a-30=45

collect like terms

5a=45-30

5a=15

a=3

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Step-by-step explanation:

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3 years ago

Can someone help me with this math problem

Elis [28]

Answer:

C. Divide both sides of the equation by -2.

Step-by-step explanation:

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3 years ago

If a hurricane was headed your way, would you evacuate? The headline of a press release issued January 21, 2009 by the survey re

Nikolay [14]

Answer:

The 98% confidence interval for population proportion of people who refuse evacuation is {0.30, 0.33].

Step-by-step explanation:

The sample drawn is of size, n = 5046.

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The confidence level (CL) = 98%

The confidence interval for single proportion is:

$CI_{p}=[\hat p-z_{(\alpha /2)}\times\sqrt{\frac{\hat p (1-\hat p)}{n} },\ \hat p+z_{(\alpha /2)}\times\sqrt{\frac{\hat p (1-\hat p)}{n} }]$

Here $z_{(\alpha /2)}$ = critical value and α = significance level.

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$\alpha =1-CL\\=1-0.98\\=0.02$

For α = 0.02 the critical value can be computed from the z table.

Then the value of $z_{(\alpha /2)}$ is ± 2.33.

The 98% confidence interval for population proportion is:

$CI_{p}=[\hat p-z_{(\alpha /2)}\times\sqrt{\frac{\hat p (1-\hat p)}{n} },\ \hat p+z_{(\alpha /2)}\times\sqrt{\frac{\hat p (1-\hat p)}{n} }]\\=[0.31-2.33\times \sqrt{\frac{0.31\times(1-0.33)}{5046} },\ 0.31+2.33\times \sqrt{\frac{0.31\times(1-0.33)}{5046} } ]\\=[0.31-0.0152,\ 0.31+0.0152]\\=[0.2948,0.3252]\\\approx[0.30,\ 0.33]$

Thus, the 98% confidence interval [0.30, 0.33] implies that there is a 0.98 probability that the population proportion of people who refuse evacuation is between 0.30 and 0.33.

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3 years ago

An infinite population has a mean of 40 and a standard deviation of 15. a sample of size 100 is taken at random from this popula

Fantom [35]

I dont know the answer sorry

3 0

4 years ago

Please help me and show your work please ill mark you brainliest :)

denis23 [38]

Answer:

Step 1 and step 2

Step-by-step explanation:

she has to subtract 30 not add 30.

2(3x+6)=3(x-10)

6x + 12 = 3x-30

6x +12 - 12 = 3x - 30 - 12

6x = 3x - 42

6x - 3x = 3x - 42 - 3x

3x = -42

3x/3 = -42/3

x = -14

3 0

3 years ago

Read 2 more answers