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3 years ago

0.8x+3.2-4.3x=7.7-1.2x

2 answers:

8 0

Combine all the like terms on one side:
0.8x-4.3x+1.2x=7.7-3.2
-2.3x=4.5
Use the division property of equality. divide both sides by -2.3.
That leaves you with x=-1.96 (when rounded). exact: -1.95652

dolphi86 [110]3 years ago

6 0

On the left side of the equation we have like terms so: -3.5x + 3.2 = -1.2x + 7.7
Add 3.5 to each side: 3.2 = 2.3x + 7.7
Subtract 7.7 from each side: -4.5 = 2.3x
Divide both sides by 2.3: -1.95652174 = x
Answer: -1.95652174

Read more about cost price here:

brainly.com/question/19104371

6 0

2 years ago

A random sample of 36 students at a community college showed an average age of 25 years. Assume the ages of all students at the

Pavel [41]

Answer:

98% confidence interval for the average age of all students is [24.302 , 25.698]

Step-by-step explanation:

We are given that a random sample of 36 students at a community college showed an average age of 25 years.

Also, assuming that the ages of all students at the college are normally distributed with a standard deviation of 1.8 years.

So, the pivotal quantity for 98% confidence interval for the average age is given by;

P.Q. = $\frac{\bar X - \mu}{\frac{\sigma}{\sqrt{n} } }$ ~ N(0,1)

where, $\bar X$ = sample average age = 25 years

$\sigma$ = population standard deviation = 1.8 years

n = sample of students = 36

$\mu$ = population average age

So, 98% confidence interval for the average age, $\mu$ is ;

P(-2.3263 < N(0,1) < 2.3263) = 0.98

P(-2.3263 < $\frac{\bar X - \mu}{\frac{\sigma}{\sqrt{n} } }$ < 2.3263) = 0.98

P( $-2.3263 \times {\frac{\sigma}{\sqrt{n} }$ < ${\bar X - \mu}$ < $2.3263 \times {\frac{\sigma}{\sqrt{n} }$ ) = 0.98

P( $\bar X - 2.3263 \times {\frac{\sigma}{\sqrt{n} }$ < $\mu$ < $\bar X +2.3263 \times {\frac{\sigma}{\sqrt{n} }$ ) = 0.98

98% confidence interval for $\mu$ = [ $\bar X - 2.3263 \times {\frac{\sigma}{\sqrt{n} }$ , $\bar X +2.3263 \times {\frac{\sigma}{\sqrt{n} }$ ]

= [ $25 - 2.3263 \times {\frac{1.8}{\sqrt{36} }$ , $25 + 2.3263 \times {\frac{1.8}{\sqrt{36} }$ ]

= [24.302 , 25.698]

Therefore, 98% confidence interval for the average age of all students at this college is [24.302 , 25.698].

8 0

3 years ago

Please answer thank you !!!

BartSMP [9]

Answer:

-3x³ - 4x² + x - 9

Step-by-step explanation:

-5x³ + 2x² + x - 7

- <u>(-2x³ + 6x² + 0 + 2)</u> remember: when you subtract, you 'add the opposite'

-3x³ + (-4x²) + x + (-9)

8 0

3 years ago

Lakelyn is training for a triathlon she is practising her swiming running and biking skills so far she can swim at a rate of 250

Nezavi [6.7K]

Answer:

The answer to the question is

It would take Lalelyn bout 3 hours to run the 18m miles, and it will take her

$\frac{x}{1.7} +\frac{y}{6} +\frac{z}{12} = t$ and x +y+z =18 where x, y, and z are the distannce covered swimming, running and bikinr respectifully

Step-by-step explanation:

To solve the question, we lisrt out the variables as follows

Swimming speed of Lakelyn = 250 yards every 5 minutes or 250×12 = 3000 yards/hour = 1.7 miles/hr

Running speed of Lakelyn = 6 miles/hour

Biking speed = 12 miles/hour

The duration it will take for Lakelyn to run 18 miles is given by

Timee taken to run 18 miles t = (Distance covered)/ (Speed of Lakelyn))

or t = D/S

Substituting the known values of such as

Running speed of Lakelyn = 6 miles/hour

From which we have the time taken to run 18 miles = 18 miles /(6 miles/hour) = 3 hours

should the 18 miles form part of the triathlon then, we have

$\frac{x}{1.7} +\frac{y}{6} +\frac{z}{12} = t$ and x +y+z =18

Where x, y and z are the distance covered Swimming, Running and Biking respectively

4 0

3 years ago

Read 2 more answers

What is AC?

Maru [420]

C. 6

Exploration: i got it right.

3 0

2 years ago