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3 years ago

8

An element with a mass of 810 grams decays by 29.3% per minute. To the nearest minute, how long will it be until there are 10 gr

ams of the element remaining?

1 answer:

lakkis [162]3 years ago

6 0

Answer:

13

Step-by-step explanation:

i got it wrong but this was the correct answer

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On three examinations, you have grades of 85, 78, and 84. There is still a final examination, which counts as one grade In order

Greeley [361]

Answer:

It's not possible to earn an A in the course
I must have a 73 or MORE to earn a B in the course

Step-by-step explanation:

The average obtained at the end of the course will be:

$\frac{85+78+84+x}{4} = av$

Where x is the grade obtained in the final examination and av is the final average. To obtain an A, av has to be at least 90, av≥90, and to obtain an B, av has to be at least 80, av≥80

Is an A in the course possible?

So, if we get 100 on the final average:

x = 100,

av = (85+78+84+100)/4 = 86,75 and 86,75∠90.

<em>Answer: No, the higher grade obtained would be 86,75.</em>

What grade you must have in the final to earn a B in the course

To earn a B, av≥80:

$av= \frac{85+78+84+x}{4 \ }\geq 80\\ \frac{247+x}{4}\geq80 \\247+x\geq 80*4\\ x\geq 320-247\\ x\geq 73$

<em>Answer: I must have a 73 or MORE to earn a B in the course</em>

6 0

3 years ago

A 6-foot tall man is standing in front of a school and notices his shadow measures 10 feet. At the same time, he notices the fla

irga5000 [103]

Answer:

The tall of the flag pole is 51 ft answer (A)

Step-by-step explanation:

∵ The tall of the man = 6 ft

∵ The his shadow = 10 ft

∵ The shadow of the flag pole = 85 ft

∵ Tall of the man/tall of the flag = shadow of the man/shadow

of the flag

∴ 6/x = 10/85 ⇒ where x is the tall of the flag

∴ x = (6 × 85) ÷ 10 = 510 ÷ 10 = 51 ft

∴ The tall of the flag pole is 51 ft

4 0

3 years ago

Read 2 more answers

Determine if this relationship forms a direct variation. Verify your answer.

leva [86]

we know that

A relationship between two variables, x, and y, represent a direct variation if it can be expressed in the form y/x=k or y=kx

so

we have

a) for x=1 y=0.50--------> y/x=0.50/1------> 0.50

b) for x=2 y=1--------> y/x=1/2-------> 0.50

c) for x=3 y=1.50--------> y/x=1.50/3-----> 0.50

d) for x=5 y=2.50--------> y/x=2.50/5----> 0.50

the value of k is equal to 0.50

so

<span>the relationship forms a direct variation. </span>

the equation is

y=0.50*x

Verify

for x=1

y=0.50*(1)------> y=0.50-----> is correct

for x=2

y=0.50*(2)------> y=1.00-----> is correct

for x=3

y=0.50*(3)------> y=1.50-----> is correct

for x=5

y=0.50*(5)------> y=2.50-----> is correct

4 0

3 years ago

Read 2 more answers

Hurry for Brainlist =Accurate Answer

cluponka [151]

Step-by-step explanation:

the second line has to be parallel (but not identical), so that the 2 lines do not cross each other, do not have any point in common.

that means it must have the same slope but a different y-intercept.

the line in the graph goes through the origin (0, 0), which makes the y-intercept = 0 (the y value when x = 0).

and we see that the points with integer coordinates seem to be e.g. (3, -2).

so, for the slope (y difference / x difference between 2 points) we use this point and the origin.

x changes by +3 (from 0 to 3).

y changes by -2 (from 0 to -2).

so, the slope is -2/3. and it is always the factor of x.

let's look at the answer options :

2x + 3y = 0

3y = -2x

y = (-2/3)x

this is the identical line, so it is wrong !

2x + 3y = 6

3y = -2x + 6

y = (-2/3)x + 2

the same slope and different y-intercept.

this is the correct solution !

2x - 3y = 9

-3y = -2x + 9

y = (2/3)x - 3

wrong slope. so it is wrong !

y = 3x + 2

wrong slope. so it is wrong !

5 0

3 years ago

PLEASEE SHOW WORK ON ALL (except #3 but also answer :D) 10 POINTS EACH QUESTION SO 50 POINTS + BRAINLY

Phantasy [73]

Grade level is this??

6 0

3 years ago