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2 years ago

Find the equation of the straight line that passes through points (-1; -2) and (3; 4)

1 answer:

6 0

Y=mx+b is our base equation

m=slope, so let's find that first:
m= change in y/change in x
So between the points (-1,-2) and (3,4),
The y values, -2 and 4, have a difference of 6. The x values, -1 and 3, have a difference of 4. This makes our slope 6/4 (or 3/2 simplified)

Now our equation is
Y=3/2x + b

We still need to find b
To find b, we can substitute a point given to us. Let's use (3,4) just to avoid negatives.

4=3/2(3) + b
Multiply
4=9/2 + b
Subtract 9/2 from both sides
-1/2=b

Now let's put it all back together!

Y=3/2x-1/2 Is the answer.

I hope this Helps!

You might be interested in

A. A container holds 0.500 qt of liquid. How many milliliters of lemonade will it hold?

Nady [450]

Answer:

A container can hold 473.176 ml

42.52 grams is nitrogen.

Step-by-step explanation:

Part A:

We have given that a container holds 0.500 qt . Now we have to find how many milliliters of lemonade it can hold.

We know that 1 qt = 946.353 ml

To find how many milliliters of lemonade a container hold, we have to convert 0.500qt into ml.

As we have mentioned above that 1 qt = 946.353 ml

Multiply the volume value by 946.353 .

0.500 * 946.353

= 473.176 ml

It means a container can hold 473.176 ml

Part B:

Convert the unit oz to grams. The ratio is 1 ounce is to 28.34 grams.

We have 10.0 oz.

10* 28.34 = 283.495

This would mean 10 oz is equivalent to 283.50 grams. It is given that the fertilizer is 15% by mass nitrogen. It means for every 100 g of fertilizer 15 grams of that is nitrogen. Hence for every 283.50 grams of fertilizer

283.50 * (15/100) = 42.52 grams is nitrogen.

8 0

2 years ago

If Julie needs 3 1/4 cups of oatmeal, how many 1/4 cups of oatmeal will she use?

Gwar [14]

The answer is thirteen
1 cup=4 one fourths
3 cups=12 one fourths
Add one more one fourth

6 0

2 years ago

Read 2 more answers

A town's population went from 25,800 to 42,600 in 15 years. What was the percent of changes?

melomori [17]

42,600 - 25,800 = 16800. That is the increase in 15 years.

You then calculate the increase as a percentage of the original population; 25,800.

16,800 / 25,800 * 100 = 65.11%

8 0

2 years ago

Our faucet is broken, and a plumber has been called. The arrival time of the plumber is uniformly distributed between 1pm and 7p

Ymorist [56]

Answer:

$E(A+B) = E(A)+E(B)=4+0.5 =4.5 hours$

$Var(A+B)= Var(A)+Var(B)=3+0.25 hours^2=3.25 hours^2$

Step-by-step explanation:

Let A the random variable that represent "The arrival time of the plumber ". And we know that the distribution of A is given by:

$A\sim Uniform(1 ,7)$

And let B the random variable that represent "The time required to fix the broken faucet". And we know the distribution of B, given by:

$B\sim Exp(\lambda=\frac{1}{30 min})$

Supposing that the two times are independent, find the expected value and the variance of the time at which the plumber completes the project.

So we are interested on the expected value of A+B, like this

$E(A +B)$

Since the two random variables are assumed independent, then we have this

$E(A+B) = E(A)+E(B)$

So we can find the individual expected values for each distribution and then we can add it.

For ths uniform distribution the expected value is given by $E(X) =\frac{a+b}{2}$ where X is the random variable, and a,b represent the limits for the distribution. If we apply this for our case we got:

$E(A)=\frac{1+7}{2}=4 hours$

The expected value for the exponential distirbution is given by :

$E(X)= \int_{0}^\infty x \lambda e^{-\lambda x} dx$

If we use the substitution $y=\lambda x$ we have this:

$E(X)=\frac{1}{\lambda} \int_{0}^\infty y e^{-\lambda y} dy =\frac{1}{\lambda}$

Where X represent the random variable and $\lambda$ the parameter. If we apply this formula to our case we got:

$E(B) =\frac{1}{\lambda}=\frac{1}{\frac{1}{30}}=30min$

We can convert this into hours and we got E(B) =0.5 hours, and then we can find:

$E(A+B) = E(A)+E(B)=4+0.5 =4.5 hours$

And in order to find the variance for the random variable A+B we can find the individual variances:

$Var(A)= \frac{(b-a)^2}{12}=\frac{(7-1)^2}{12}=3 hours^2$

$Var(B) =\frac{1}{\lambda^2}=\frac{1}{(\frac{1}{30})^2}=900 min^2 x\frac{1hr^2}{3600 min^2}=0.25 hours^2$

We have the following property:

$Var(X+Y)= Var(X)+Var(Y) +2 Cov(X,Y)$

Since we have independnet variable the Cov(A,B)=0, so then:

$Var(A+B)= Var(A)+Var(B)=3+0.25 hours^2=3.25 hours^2$

3 0

3 years ago

Which operation involving complex numbers requires the use of a conjugate to be carried out?

Pani-rosa [81]

Answer:

The correct answer will be "Division".

Step-by-step explanation:

The procedure represents numerous values requiring something like a conjugate to have been done becomes division, since the denominator conjugate multiplies the numeric values including its quotient to represent the quotient of several complex numbers throughout the standard language.
It is indeed a method used to separate a set of items across equal proportions.

3 0

2 years ago