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avanturin [10]
3 years ago
5

Solve or check ' whether your answer is correct or not 3x -9=12​

Mathematics
2 answers:
Gnoma [55]3 years ago
7 0
X = 7..................
Kruka [31]3 years ago
5 0

Answer:

x = 7

Step-by-step explanation:

3x - 9 = 12

3x = 12 + 9

3x = 21

x = 21 ÷ 3

x = 7

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Calculate the rate of change.
liq [111]

Answer:

It is 5/5 or 1/1 as it goes up 5 and to the left 5!!!

5 0
2 years ago
An article reports the following data on yield (y), mean temperature over the period between date of coming into hops and date o
skelet666 [1.2K]

Answer:

x1=c(16.7,17.4,18.4,16.8,18.9,17.1,17.3,18.2,21.3,21.2,20.7,18.5)

x2=c(30,42,47,47,43,41,48,44,43,50,56,60)

y=c(210,110,103,103,91,76,73,70,68,53,45,31)

mod=lm(y~x1+x2)

summary(mod)

R output: Call:

lm(formula = y ~ x1 + x2)

Residuals:  

   Min      1Q Median      3Q     Max

-41.730 -12.174   0.791 12.374 40.093

Coefficients:

        Estimate Std. Error t value Pr(>|t|)    

(Intercept) 415.113     82.517   5.031 0.000709 ***  

x1            -6.593      4.859 -1.357 0.207913    

x2            -4.504      1.071 -4.204 0.002292 **  

---  

Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1  

Residual standard error: 24.45 on 9 degrees of freedom  

Multiple R-squared: 0.768,     Adjusted R-squared: 0.7164  

F-statistic: 14.9 on 2 and 9 DF, p-value: 0.001395

a).  y=415.113 +(-6.593)x1 +(-4.504)x2

b). s=24.45

c).  y =415.113 +(-6.593)*21.3 +(-4.504)*43 =81.0101

residual =68-81.0101 = -13.0101

d). F=14.9

P=0.0014

There is convincing evidence at least one of the explanatory variables is significant predictor of the response.

e).  newdata=data.frame(x1=21.3, x2=43)

# confidence interval

predict(mod, newdata, interval="confidence")

#prediction interval

predict(mod, newdata, interval="predict")

confidence interval

> predict(mod, newdata, interval="confidence",level=.95)

      fit      lwr      upr

1 81.03364 43.52379 118.5435

95% CI = (43.52, 118.54)

f).  #prediction interval

> predict(mod, newdata, interval="predict",level=.95)

      fit      lwr      upr

1 81.03364 14.19586 147.8714

95% PI=(14.20, 147.87)

g).  No, there is not evidence this factor is significant. It should be dropped from the model.

4 0
2 years ago
You are choosing between two health clubs. Club A offers membership for a fee of $ 28$28 plus a monthly fee of $ 20.$20. Club B
eimsori [14]

Answer:

That is to say that at 3 months, the values of the club are equal.

Club A = 268 dollars in total

Club B = 295 dollars in total

Step-by-step explanation:

The first thing is to propose an equation for each club. Let m be the number of months.

Club A = 28 + 20 * m

Club B = 19 + 23 * m

Now, to know when it is the same, we must equal the value of Club A with Club B, it would look like this

28 + 20 * m = 19 + 23 * m

By rearranging the equation we have:

23 * m - 20 * m = 28-19

3 * m = 9

m = 3

That is to say that at 3 months, the values of the club are equal.

Now to know the total value, we will do it with an annual membership, which would be a total of 12 months, therefore it is to replace in the equation of each one:

Club A = 28 + 20 * 12 = 268 dollars in total

Club B = 19 + 23 * 12 = 295 dollars in total

3 0
3 years ago
3x2 + 7x + 2 how to factor<br>​
omeli [17]

Answer:

(x+2)(3x+1)

Step-by-step explanation:

4 0
2 years ago
A cat requires a 3 mL injection of a 0.5% solution. How many milligrams will it receive per injection?
Kay [80]
<h2>Hello!</h2>

The answer is: 15mg

<h2>Why?</h2>

0.5% means that there are 0.5 grams per 100 mL,  and a 0.5 grams are equal to 500 milligrams.

So, to calculate how many milligrams will be received per injection, we need to make the following calculations:

3mL*\frac{500mg}{100mL}=15mg

Have a nice day!

7 0
2 years ago
Read 2 more answers
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