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3 years ago

What is the value of -9r - 7 when r = 2? -25 -18 11 45

Mathematics

2 answers:

AlexFokin [52]3 years ago

5 0

Substitute the variable for value we're given.

-9(2) - 7
-18 - 7 = -25

So, -25 is the answer.

statuscvo [17]3 years ago

5 0

Substitute the 2 for r.
-9(2) - 7
A negative and a positive equal a negative.
-18 - 7 = -25
Your answer is going to be -25

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If (x) = 3х - 2 and g(x) = 2х+ 1, find (f- g)(x).

MAXImum [283]

Answer:

Step-by-step explanation:

f(x) - g(x) = 3x-2 - (2x + 1) Remove the brackets

f(x) - g(x) = 3x - 2 - 2x -1 Combine terms.

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3 years ago

A lathe is set to cut bars of steel into lengths of 6 cm. The lathe is considered to be in perfect adjustment if the average len

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Answer:

$t=\frac{5.97-6}{\frac{0.4}{\sqrt{93}}}=-0.723$

E. -0.723

$df=n-1=93-1=92$

$p_v =2*P(t_{(92)}$

Since the p value is very high we don't have enough evidence to conclude that the true mean for the lengths is different from 6 cm.

Step-by-step explanation:

Information provided

$\bar X=5.97$ represent the sample mean for the length

$s=0.4$ represent the sample standard deviation

$n=93$ sample size

$\mu_o =6$ represent the value that we want to test

$\alpha=0.05$ represent the significance level

t would represent the statistic

$p_v$ represent the p value for the test

System of hypothesis

We need to conduct a hypothesis in order to check if the lathe is in perfect adjustment (6cm), then the system of hypothesis would be:

Null hypothesis: $\mu = 6$

Alternative hypothesis: $\mu \neq 6$

since we don't know the population deviation the statistic is:

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

Replacing in formula (1) we got:

$t=\frac{5.97-6}{\frac{0.4}{\sqrt{93}}}=-0.723$

E. -0.723

P value

The degrees of freedom are given by:

$df=n-1=93-1=92$

Since is a two tailed test the p value would be:

$p_v =2*P(t_{(92)}$

Since the p value is very high we don't have enough evidence to conclude that the true mean for the lengths is different from 6 cm.

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3 years ago

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Sydney's Age is 6

Step-by-step explanation:

6 x 2 = 12

12 + 6 = 18

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3 years ago

Read 2 more answers

Please help me answer 16 please

amm1812

Answer:

SSS

Step-by-step explanation:

I can identify that these triangles are congruent by using the SSS (Side, Side, Side) postulate theorem. I know this because first, second, and home triangle share the same side as the third, second, and home triangle, meaning they are congruent, so are the other sides of the angle since the question states they are congruent.

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3 years ago

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(The question asks how the height changes at the exact moment the height is 50 cm, but this info is a red herring because the rate of change is constant.)

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3 years ago