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4 years ago

What is the answer when subtracting (-3y2-8)-(5y2+1)?

Mathematics

1 answer:

Alona [7]4 years ago

3 0

You have to distribute the minus sign to the second parenthesis, changing the sign of every term:

$-3y^2-8-(5y^2+1) = -3y^2-8-5y^2-1 = -8y^2-9$

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What is 50% off $55.oo?

AnnZ [28]

50% of $55 = $27.50

Hope This Helps You!
Good Luck Studying :)

6 0

3 years ago

An educator claims that the average salary of substitute teachers in school districts is less than $60 per day. A random sample

valentina_108 [34]

Answer:

$t=\frac{58.875-60}{\frac{5.083}{\sqrt{8}}}=-0.626$

The degrees of freedom are given by:

$df=n-1=8-1=7$

The p value would be given by:

$p_v =P(t_{(7)}$

Since the p value is higher than 0.1 we have enough evidence to FAIl to reject the null hypothesis and we can't conclude that the true mean is less than 60

Step-by-step explanation:

Information given

60, 56, 60, 55, 70, 55, 60, and 55.

We can calculate the mean and deviation with these formulas:

$\bar X= \frac{\sum_{i=1}^n X_i}{n}$

$s=\sqrt{\frac{\sum_{i=1}^n (X_i -\bar X)^2}{n-1}}$

Replacing we got:

$\bar X=58.875$ represent the mean

$s=5.083$ represent the sample standard deviation for the sample

$n=8$ sample size

$\mu_o =60$ represent the value that we want to test

$\alpha=0.1$ represent the significance level

t would represent the statistic

$p_v$ represent the p value

Hypothesis to test

We want to test if the true mean is less than 60, the system of hypothesis would be:

Null hypothesis: $\mu \geq 60$

Alternative hypothesis: $\mu < 60$

The statistic would be given by:

$t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (1)

Replacing the info we got:

$t=\frac{58.875-60}{\frac{5.083}{\sqrt{8}}}=-0.626$

The degrees of freedom are given by:

$df=n-1=8-1=7$

The p value would be given by:

$p_v =P(t_{(7)}$

Since the p value is higher than 0.1 we have enough evidence to FAIl to reject the null hypothesis and we can't conclude that the true mean is less than 60

3 0

3 years ago

Three consecutive numbers are such that when they are taken in increasing order and multiplied by 2,3and 4 respectively, they ad

Ivenika [448]

Answer:

7 , 8 , 9

Step-by-step explanation:

Assume three consecutive number are,

x , (x+1) , (x+2)

Multiplied by 2 ,3 and 4 respectively

2x , 3(x + 1) , 4(x + 2)

Sum of all = 74

So,

2x + 3(x + 1) + 4(x + 2) = 74

2x + 3x + 3 + 4x + 8 = 74

9x + 11 = 74

9x = 63

x = 7

So,

x , (x+1) , (x+2)

7 , (7+1) , (7+2)

7 , 8 , 9

3 0

3 years ago

Eric was rock climbing. At one point, he stopped and climbed straight down 2\dfrac{1}{2}2

nikitadnepr [17]

The equation that matches the given situation is $-2\frac{1}{2}+6\frac{3}{4}=?$ . So, after two moves, Eric's elevation changed $4\frac{1}{4}$ meters above.

We know that in mathematics, subtraction means removing something from a group or a number of things. What is left in the group gets smaller when we subtract. The minuend is the first element we use. The subtrahend is the part that is being removed. The difference is the portion that remains after subtraction.

Assume that "negative" means climbing down and "positive" means climbing up. We must locate the elevation change in this area.

Given that Eric climbed straight down $2\frac{1}{2}$ meters. So we can write $-2\frac{1}{2}$ .

Again Eric climbed straight up $6\frac{3}{4}$ meters. So, we can write $6\frac{3}{4}$ .

Then the change = $-2\frac{1}{2}+6\frac{3}{4}$

= $-\frac{(2*2+1)}{2}+\frac{6*4+3}{4}$

= $-\frac{5}{2} +\frac{27}{4}$

= $\frac{-(5*2)+27}{4}$

= $\frac{-10+27}{4}$

= $\frac{17}{4}$

= $\frac{4*4+1}{4}$

= $4\frac{1}{4}$

Therefore, the equation that matches the given situation is $-2\frac{1}{2}+6\frac{3}{4}=?$ . So, after two moves, Eric's elevation changed $4\frac{1}{4}$ meters above.

Learn more about subtraction here -

brainly.com/question/24116578

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2 years ago

Leading Coefficient Like Terms Constant Term

Nadya [2.5K]

Answer:

An aeroplanes velocity changes from 1250m/s as it comes down to land . It accelerates at 4.9m/s² . Calculate how long it took to come to a stop ?

Step-by-step explanation:

pls help me i beg u i am sorry i never answered ur question thx though

5 0

3 years ago