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2 years ago

Please help which one is it!!

Mathematics

2 answers:

Lelu [443]2 years ago

7 0

Step-by-step explanation:

what the other answer tries to say :

you keep the cubic root on one side, and you combine all other terms (here with 5 and 7 only constants) in the other side :

-cubic root(x² - 9) = 2

now we put both sides to the power of 3 and we get

-(x² - 9) = 8

remember, putting a negative number to an odd power (like 3 or 5 or 7 or ...) delivers as result again a negative value.

and now, I think, the other answer made a mistake. that happens, when you don't write down your thoughts.

so,

-(x² - 9) = 8

-x² + 9 = 8

-x² = -1 (and NOT -17)

x² = 1

x = 1 and x = -1

remember, squaring a negative number delivers the same result as squaring the same positive number. therefore, the square root has always 2 solutions : a positive and a negative one.

so, the right answers are the second and the third ones.

sasho [114]2 years ago

6 0

Last one and first. You can find out why by isolating the cube root and cubing both sides.

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Answer:

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2 years ago

90% of the seniors at Richmond high school will attend the school prom. If 270 seniors attend

ELEN [110]

Answer:

243

Step-by-step explanation:

make 90% into a decimal

0.9

multiply 270 by 0.9 to get the answer of 243

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3 years ago

8.) Jim eats (r) apples and Maria eats 3 times as

mash [69]

Answer:

Step-by-step explanation:

if Jim eats r apples and Maria eats 3times as Jim then we can represent the number of times Maria eats as 3r

Together, the both eat 96 apples that is:

r + 3r = 96 apples - this is the equation for this situation.

Solving further

r + 3r = 96apples

4r = 96 apples (divide through the equation by 4)

4/4 r = 96/4 apples

Then

r = 24 apples

Which means that Jim eats 24 apples while Maria eats 3 * 24 apples = 72 apples.

6 0

3 years ago

A cylindrical container with a diameter of 0.5 feet and a height of 5 feet is filled with gas that costs $60 per cubic foot. Wha

zloy xaker [14]

Answer: $235,62

Step-by-step explanation:

You need to use the formula for calculate the volume of a cylinder:

$V=\pi r^2h$

Where "r" is the radius and "h" is the height.

You know that the cylindrical container has a diameter of 0.5 feet and a height of 5 feet (Remember that the radius if half the diameter):

$r=\frac{0.5ft}{2}=0.25ft\\\\h=5ft$

Then, you need to substitute these values into $V=\pi r^2h$ to get the volume of the cylindrical container:

$V=\pi (0.5ft)^2(5ft)$

$V=3.92ft^3$

Since the gas costs $60 per cubic foot, you need to multiply the volume of the container by $60 to get the total value of the gas in the container if it's filled completely. Then:

$total\ value=(3.92)(\$60)=$235,62$