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3 years ago

Suppose x=0.5(300-x). what is the value of x?

Mathematics

1 answer:

Sonbull [250]3 years ago

6 0

Expand

x = 150 - 0.5x

Add 0.5x to both sides

x + 0.5x = 150

Simplify x + 0.5x to 1.5x

1.5x = 150

Divide both sides by 1.5

x = 150/1.5

Simplify 150/1.5 to 100

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A necklace found at a pawn shop is 192 grams and has a volume of 19.5 cubic centimetres. What metal is the necklace made of?

Sophie [7]

Answer:

we divide 192 by the volume 19.5

192÷19.5=9.85 so the necklace is made of bronze

8 0

3 years ago

Carlos takes classes at both Westside Community College and Pinewood Community College. At Westside, class fees are $ 98 per cre

Sholpan [36]

Answer:

x + y = 13

98x + 115y = z

Step-by-step explanation:

Let x represent the time spent taking class in Westside community college

Let y represent the time spent taking class in Pinewood community college

Let z represent the combined total amount paid for the class fees.

The total combined time for the two school is given as:

x + y = 13.

For the combined total amount; we multiply the price for each school with the time spent on the school and sum them together.

Westside: $98 * x = 98x$

Pinewood: $115 * y = 115y$

The combined total amount represented as z is given as:

z = 98x + 115y

7 0

3 years ago

A tourist boat is used for sightseeing in a nearby river. The boat travels 2.4 miles downstream and in the same amount of time,

topjm [15]

Answer: the current of the river is 3 mph.

Step-by-step explanation:

Let x represent the current of the river.

The boat travels 2.4 miles downstream. Assuming it travelled with the current of the river. If the boat travels at an average speed of 21 miles per hour in the still water, it means that the total speed at which the boat travelled downstream is

(21 + x) mph

Time = distance/speed

Time taken to travel downstream is

2.4/(21 + x)

it travels 1.8 miles upstream. Assuming it travelled against the current of the river. it means that the total speed at which the boat travelled upstream is

(21 - x) mph

Time taken to travel upstream is

1.8/(21 - x)

Since the time taken to travel upstream and downstream is the same, then

2.4/(21 + x) = 1.8/(21 - x)

Cross multiplying, it becomes

2.4(21 - x) = 1.8(21 + x)

50.4 - 2.4x = 37.8 + 1.8x

2.4x + 1.8x = 50.4 - 37.8

4.2x = 12.6

x = 12.6/4.2

x = 3 mph

7 0

3 years ago

Read 2 more answers

Solve 3x +5 =14 please help me

alisha [4.7K]

3x=14-5
3x=14-5
3x=9
x=9 ➗ 3
x= 3

the answer is 3

4 0

3 years ago

Read 2 more answers

The time needed to complete a final examination in a particular college course is normallydistributed with a mean of 80 minutes

Artist 52 [7]

Answer:

a) 0.023

b) 0.286

c) 10 students will be unable to complete the exam inthe allotted time.

Step-by-step explanation:

We are given the following information in the question:

Mean, μ = 80 minutes

Standard Deviation, σ = 10 minutes

We are given that the distribution of time to complete an exam is a bell shaped distribution that is a normal distribution.

Formula:

$z_{score} = \displaystyle\frac{x-\mu}{\sigma}$

a) P(completing the exam in one hour or less)

P(x < 60)

$P( x < 60) = P( z < \displaystyle\frac{60 - 80}{10}) = P(z < -2)$

Calculation the value from standard normal z table, we have,

$P(x < 60) =0.023= 2.3\%$

b) P(complete the exam in more than 60 minutes but less than 75 minutes)

$P(60 \leq x \leq 75) = P(\displaystyle\frac{60 - 80}{10} \leq z \leq \displaystyle\frac{75-80}{10}) = P(-2 \leq z \leq -0.5)\\\\= P(z \leq -0.5) - P(z < -2)\\= 0.309- 0.023 = 0.286= 28.6\%$