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4 years ago

-3x +2y= 4 4x-13y=5 solve by elimination

Mathematics

1 answer:

Svet_ta [14]4 years ago

4 0

I am better at substitution, but you want to get the equations as similar as possible, but are the opposite, so you can cancel it out.

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How do you fraction decimals and percents and all of that

Korvikt [17]

From fraction to decimal: divide the numerator by the denominator

From decimal to percent: move the decimal two places to the right. For example: 0.062=6.2%

From percent to decimal: move the decimal point two steps to the left. For example: 56%=0.56

From decimal to fraction: Rewrite the decimal number number as a fraction (example: 2.625=2.6251) an then Multiply by 1 to eliminate 3 decimal places, we multiply numerator and denominator by 10 cubed = 10002.625/1×1000/1000=2625/1000 and don forget to reduce if possible;)

3 0

3 years ago

What grade level is a score of 235 in maps math I am really wanting to know

igomit [66]

Answer: It should be an 8th grade level

(sorry if i'm wrong)

6 0

3 years ago

X - 7 = 13 - x help asap plz

bekas [8.4K]

Answer:

x = 10

Step-by-step explanation:

$x - 7 = 13 - x$

Step 1 : Collect like terms and simplify

$x + x = 13 + 7 \\ 2x = 20$

Step 2 : Divide both sides of the equation by 2

$\frac{2x}{2} = \frac{20}{2}$

Step 3 : Simplify by cross cancellation of common term : 2

$x = 10$

4 0

3 years ago

In analyzing the city and highway fuel efficiencies of many cars and trucks, the mean difference in fuel efficiencies for the 60

Olegator [25]

Answer:

$7.38-1.96\frac{2.51}{\sqrt{601}}=7.18$

$7.38+1.96\frac{2.51}{\sqrt{601}}=7.58$

For this case the confidence interval is given by :

$7.18 \leq \mu \leq 7.58$

Step-by-step explanation:

Data provided

$\bar X=7.38$ represent the sample mean for the fuel efficiencies

$\mu$ population mean

s=2.51 represent the sample standard deviation

n=601 represent the sample size

Confidence interval

The formula for the confidence interval of the true mean is given by:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

The degrees of freedom for this case is given by:

$df=n-1=601-1=600$

The Confidence level for this case is 0.95 or 95%, and the significance level $\alpha=0.05$ and $\alpha/2 =0.025$ and the critical value is given by $t_{\alpha/2}=1.96$

Replcing into the formula for the confidence interval is given by:

$7.38-1.96\frac{2.51}{\sqrt{601}}=7.18$

$7.38+1.96\frac{2.51}{\sqrt{601}}=7.58$

For this case the confidence interval is given by :

$7.18 \leq \mu \leq 7.58$

8 0

3 years ago

On Sunday, a local hamburger shop sold a combined total of 378 hamburgers and cheeseburgers. The number of cheeseburgers was sol

ipn [44]

Answer:

The number of hamburgers sold was 126.

Step-by-step explanation:

Let h = number of hamburgers sold

let c = cheeseburgers sold

c+h = 378

c = 2h

Substitute c =2h into c+h =278

c+h =378

2h+h = 378

Combine like terms

3h = 378

Divide by 3

3h/3 =378/3

h =126

The number of hamburgers sold was 126.

5 0

3 years ago