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3 years ago

Combine the like terms to simplify the expression. 9x^2+8y^2+4y^2-3x

Mathematics

2 answers:

Novay_Z [31]3 years ago

7 0

what is question is (C)

matrenka [14]3 years ago

3 0

Answer:

$\boxed{\bold{9x^2+12y^2-3x}}$

Step By Step Explanation:

[ Evaluate Like Terms ]

- $\bold{8y^2}$

- $\bold{4y^2}$

[ Combine Like Terms According To Equation ]

$\bold{8y^2+4y^2=12y^2}$

[ Rewrite Equation With Like Terms Combined ]

$\bold{9x^2+12y^2-3x}$

- Mordancy

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I can’t remember how to do this if I try a bit longer I can probably figure it out but not sure exactly. Please If anyone can he

UNO [17]

Answer:

£2.38

Step-by-step explanation:

2.5 cost £1.40

4.25 cost £ x

so x=(4.25*1.40)/2.5=5.95/2.5=£2.38

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3 years ago

Dr. Steve is working with a new radioactive substance in his lab. He currently has 64 grams of the substance and knows that it d

4vir4ik [10]

Remember that the general decay equation is:
$y=A(1-r)^{x}$
where
$y$ is the amount after a time $x$
$A$ is the initial amount
$r$ is the the decay percent in decimal form

The first ting we are going to do is find $r$ by dividing our <span>decay rate of 25% by 100%: </span> $r= \frac{25}{100} =0.25$ .
We also know from our problem that $y=64$ . Lets replace $y$ and $r$ in our formula:
$64=A(1-0.25)^{x}$
$64=A(0.75)^{x}$
We know now that our decay rate is 0.75, and since 0.75<1, we can conclude that this situation represents exponential decay.

Now, to find the initial amount, we are going to solve our equation for $A$ :
$64=A(0.75)^{x}$
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3 years ago

Read 2 more answers

I need to get this done

Allushta [10]

Answer:

x = 17 and y = 8

Step-by-step explanation:

Since (6x + 3) and (8x - 31) are alternate interior angles, they are congruent.

Therefore, you can set them equal to each other and solve for x.

8x - 31 = 6x + 3

Combine like terms

2x = 34

Divide both sides by two

x = 17

Since (5y + 35) and (6x + 3) are consecutive interior angles, they add up to 180. Plug in 17 for x.

(5y + 35) + (6(17) + 3) = 180

Add like terms

5y + 140 = 180

5y = 40

y = 8

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3 years ago

PLSSS HELP ME WITH MATH

labwork [276]

Step-by-step explanation:

always remember, equations and inequalities are like a scale with 2 pans (left and right).

a variable is like a placeholder, an empty spot on the pans. and the expressions on both sides are kind of the conditions for the things to put in these empty spots so that the status of the scale stays unchanged.

for an equation the scale has to stay balanced all the time.

and in an inequality one side is heavier that the other (it normally does not matter how much heavier) with "<" or ">" signs, or the scale can be also balanced with "<=" or ">=" signs. just the other side must never be heavier.

so, in our case here

2x - 5 = 3

yes, the solution (the ONLY solution, actually) is x = 4. no other value of x allows the scale to be balanced.

2x - 5 >= 3

well, since it is a ">=" sign, we can be lazy and treat it like the equation above, and x = 4 is therefore a valid solution for the inequality too.

but so is every other value of x that makes the left side "heavier". what about e.g. 5 ?

2×5 - 5 >= 3

10 - 5 >= 3

5 >= 3

true, great ! so, e.g. x = 5 is also a valid solution.

what else ?

let's simplify the inequality

2x - 5 >= 3

2x >= 8

x >= 4

so, really every value of x that is greater or equal to 4 is a valid solution for the inequality.

-2x - 5 = 3

yes, the solution (the ONLY solution, actually) is x = -4. no other value of x allows the scale to be balanced.

-2x - 5 >= 3

well, since it is a ">=" sign, we can be lazy and treat it like the equation above, and x = -4 is therefore a valid solution for the inequality too.

but so is every other value of x that makes the left side "heavier". what about e.g. -5 ?

-2×-5 - 5 >= 3

remember, -×- = +

10 - 5 >= 3

5 >= 3

true, great ! so, e.g. x = -5 is also a valid solution.

what else ?

let's simplify the inequality

-2x - 5 >= 3

-2x >= 8

x <= -4

a multiplication or division by a negative value flips the inequality sign, because such an operation makes a light weight heavy and a heavy weight light.

so, really every value of x that is less or equal to -4 is a valid solution for the inequality.

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2 years ago

At a new exhibit in the Museum of Science, people are asked to choose between 94 or 220 random draws from a machine. The machine

Tresset [83]

Answer:

0.0869 = 8.69% probability of getting more than 61% green balls.

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the z-score of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$ .

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean $\mu = p$ and standard deviation $s = \sqrt{\frac{p(1-p)}{n}}$