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3 years ago

Two- step equation Solve each question

Mathematics

1 answer:

Mandarinka [93]3 years ago

5 0

To solve for a variable, isolate it! Get the variable alone on one side of the equation.

13) -15 = -4m + 5 ... -20 = -4m ... m = 5

14) 10 - 6v = -104 ... -6v = -114 ... v = 19

15) 8n + 7 = 31 ... 8n = 24 ... n = 3

16) -9x - 13 = -103 ... -9x = -93 ... x = 31/3

17) (n + 5) / -16 = -1 ... n + 5 = 16 ... n = 11

18) -10 = -10 + 7m ... 0 = 7m ... m = 0

19) -10 = -10(k - 9) ... 1 = k - 9 ... k = 10

20) (m / 9) - 1 = -2 ... m / 9 = -1 ... m = -9

21) 9 + 9n = 9 ... 9n = 0 ... n = 0

22) 7(9 + k) = 84 ... 9 + k = 12 ... k = 3

I cannot clearly read 23 and 24, but I hope you can see the principles I applied to produce these answers.

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Use the commutative law of MULTIPLICATION to write an equivalent expression.<br><br> 9(x+5)

DochEvi [55]

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3 years ago

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3 years ago

OK my paper says the numerical expression 5+12 represent the sum of 5 and 12. I don't understand

Afina-wow [57]

That literally means the numbers '5' and '12' written like this: 5 + 12

represent the sum of 5 and 12, which is the same as 5 + 12 (because the sum is when all the numbers are added up).

So it's saying 5 + 12 equals to 17.

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Simplify this expression.<br> 3^-3

Sphinxa [80]

Answer:

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Step-by-step explanation:

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3 years ago

Starting in the 1970s, medical technology allowed babies with very low birth weight (VLBW, less than 1500 grams, about 3.3 pound

cluponka [151]

Answer:

The test statistic value using the VLBW babies as group 1 is z=-2.76±0.01 and the P-value for the test (±0.0001) is 0.0030.

Step-by-step explanation:

This is a hypothesis test for the difference between proportions.

The claim is that the proportion of persons with normal birth weight that graduates from high school is significantly greater than the proportion of persons with very low birth weight that graduates from high school.

Then, the null and alternative hypothesis are:

$H_0: \pi_1-\pi_2=0\\\\H_a:\pi_1-\pi_2> 0$

The significance level is 0.05.

The sample 1 (VLBW group), of size n1=244 has a proportion of p1=0.77049.

$p_1=X_1/n_1=188/244=0.77049$

The sample 2 (control group), of size n2=247 has a proportion of p2=0.79757.

$p_2=X_2/n_2=197/247=0.79757$

The difference between proportions is (p1-p2)=-0.02708.

$p_d=p_1-p_2=0.77049-0.79757=-0.02708$

The pooled proportion, needed to calculate the standard error, is:

$p=\dfrac{X_1+X_2}{n_1+n_2}=\dfrac{188+197}{244+247}=\dfrac{385}{491}=0.988$

The estimated standard error of the difference between means is computed using the formula:

$s_{p1-p2}=\sqrt{\dfrac{p(1-p)}{n_1}+\dfrac{p(1-p)}{n_2}}=\sqrt{\dfrac{0.988*0.012}{244}+\dfrac{0.988*0.012}{247}}\\\\\\s_{p1-p2}=\sqrt{0.00005+0.00005}=\sqrt{0.0001}=0.0098$

Then, we can calculate the z-statistic as:

$z=\dfrac{p_d-(\pi_1-\pi_2)}{s_{p1-p2}}=\dfrac{-0.02708-0}{0.0098}=\dfrac{-0.02708}{0.0098}=-2.76$

This test is a left-tailed test, so the P-value for this test is calculated as (using a z-table):

$P-value=P(t$

As the P-value (0.0030) is smaller than the significance level (0.05), the effect issignificant.

The null hypothesis is rejected.

There is enough evidence to support the claim that the proportion of persons with normal birth weight that graduates from high school is significantly greater than the proportion of persons with very low birth weight that graduates from high school.

3 0

3 years ago