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2 years ago

X - 2y = -3 2x + y = -1

Mathematics

2 answers:

lianna [129]2 years ago

7 0

Answer:

it can only be simp[lified

so it will be

(x+2x)+(y+2y)=-3-1

3x+3y=-4

cannot be solved further

Step-by-step explanation:

bezimeni [28]2 years ago

3 0

Answer:

y = 1

x = -1

Step-by-step explanation:

x - 2y = -3, then x = 2y - 3

2x + y = -1

substitute for x:

2(2y - 3) + y = -1

4y - 6 + y = -1

5y = 5

y = 1

x = 2 - 3 = -1

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9= 3 3_4- 2 7_8- b <br> B?

rosijanka [135]

Answer:

Step-by-step explanation:

9 - 3¾ - 2⅞ = 3⅜

He gave his grandmother 3⅜ pounds of apples.

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2 years ago

How do u write 528 as a decimals numerals

Dmitry_Shevchenko [17]

Answer:

0.528 because its just moveing the decimal point to the right.

just so you can understand better.

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2 years ago

A 12 foot ladder is leaning against the building. The ladder makes a 45° angle with the building. How far up the building does t

DaniilM [7]

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2 years ago

A researcher compares the effectiveness of two different instructional methods for teaching anatomy. A sample of 66 students usi

d1i1m1o1n [39]

Answer:

99% confidence interval = [-35.47,-26.53]

Step-by-step explanation:

For Method 1:

$n_1=66,\mu_1=54.9,\sigma_1=6.04$

For Method 2:

$n_2=110,\mu_2=85.9,\sigma_2=16.44$

We need to find the 99% confidence interval for the true difference between testing averages for students using Method 1 and students using Method 2.

Step 1: Find the point estimate for the true difference between the population means.

$Difference=\mu_1-\mu_2$

$Difference=54.9-85.9$

$Difference=-31.0$

Therefore the point estimate for the true difference between the population means is -31.

Step 2: Find margin of error at 99% confidence.

From the standard normal table the critical value of z at 99% confidence = 2.576.

The formula for margin of error:

$M.E.=z^*\times \sqrt{\dfrac{\sigma_1^2}{n_1}+\dfrac{\sigma_2^2}{n_2}}}$

Substitute the values.

$M.E.=2.576\times \sqrt{\dfrac{(6.04)^2}{66}+\dfrac{(16.44)^2}{110}}}$

$M.E.\approx 4.47$

Therefore, the margin of error is 4.47.

Step 3: Find 99% confidence interval.

$C.I.=(\mu_1-\mu_2)\pm M.E.$

$C.I.=-31.0\pm 4.47$

$C.I.=-35.47,-26.53$

Therefore, the 99% confidence interval is [-35.47,-26.53].

3 0

2 years ago

How do you prove any number to the zero power is 1? Like why is any number to the zero power one?

Gnesinka [82]

Answer:

Step-by-step explanation:

It's a matter of being consistent in a pattern:

Let a be a number. If a^(-3) is the first number, it's equal to 1 / a^3.

1 / a^2

1 / a^1

?? To fit into this pattern, a^0 must equal 1.

a^1

a^2

a^3

and so on.

Try this same exercise with a = 2:

2^(-2) = 1/4

2^(-1) = 1/2

?? This number has to be 1 to fit the pattern. 2^0 = 1. Note that each

term is 2x the previous term: 2(1/4) = 1/2; 2(1/2) = 1; 2(1) = 2; 2(2) = 4,

and so on. Again, 2^0 must = 1 to fit into this sequence.

2^1 = 2

2^2 = 4

3 0

3 years ago