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3 years ago

The solution to the system -2x+5y=-15 and 5x+2y=-6 is what

Mathematics

1 answer:

cupoosta [38]3 years ago

8 0

Step-by-step explanation:

−2x+5y=−15 and 5x+2y=−6

Rewrite equations:

−2x+5y=−15;5x+2y=−6

Step: Solve−2x+5y=−15for x:

−2x+5y=−15

−2x+5y+−5y=−15+−5y(Add -5y to both sides)

−2x=−5y−15

−2x−2=−5y−15−2(Divide both sides by -2)

x=52y+152

Step: Substitute52y+152forxin5x+2y=−6:

5x+2y=−6

5(52y+152)+2y=−6

292y+752=−6(Simplify both sides of the equation)

292y+752+−752=−6+−752(Add (-75)/2 to both sides)

292y=−872

292y292=−872292(Divide both sides by 29/2)

y=−3

Step: Substitute−3foryinx=52y+152:

x=52y+152

x=52(−3)+152

x=0(Simplify both sides of the equation)

Answer:

x=0 and y=−3

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Which of the following statements is true? A. 15-0=0 B. 0÷15=0 C. 15+0=0 D. 15÷0=0

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Answer:

B) 0:15=0

Step-by-step explanation:

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3 years ago

Determine the # of X intercepts from this equation F(x)=x^2+5x+4 ?

k0ka [10]

There are 2 x intercepts, x=-4 and x=-1

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3 years ago

Anyone know the answer?

sattari [20]

The answer is c because k and m are the same so l and n are also the same

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4 years ago

GreenBeam Ltd. claims that its compact fluorescent bulbs average no more than 3.24 mg of mercury. A sample of 25 bulbs shows a m

amm1812

Answer:

Null hypothesis: $\mu \leq 3.24$

Alternative hypothesis: $\mu > 3.24$

Step-by-step explanation:

1) Previous concepts and data given

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

A right tailed test (sometimes called an upper test) is when the alternative hypothesis statement contains a greater than (>) symbol.

$\bar X=3.29$ represent the sample mean

s represent the sample standard deviation

n represent the sample selected

$\alpha$ significance level

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the mean for fluorescent bulbs is no more than 3.24 mg of mercury, the system of hypothesis would be:

Null hypothesis: $\mu \leq 3.24$

Alternative hypothesis: $\mu > 3.24$

IIf we know the population deviation we can apply a z test to compare the actual mean to the reference value, and the statistic is given by:

$z=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}}$ (1)

z-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

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4 years ago

Now, look at the set of integers. Complete the table for the closure property if integers under the four operations.

Kisachek [45]

Answer:

See below.

Step-by-step explanation:

Addition: closed

Example: -5 + 10 = 5, and -5, 10, and 5 are all integers

Subtraction: closed

Example: 10 - 8 = 2, and 10, 8, and 2 are all integers

Multiplication: closed

Example: -4 * 7 = -28, and -4, -7 and -28 are all integers

Division: not closed

Example: 5/2 = 2.5, and 2.5 is not an integer, although 2 and 5 are integers

The set of integers is closed under addition, subtraction, and multiplication because any addition, subtraction, or multiplication of integers always results in an integer.

The set of integers is not closed under division because a division of integers does not always result in an integer.

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3 years ago