All categories

3 years ago

Solve by substitution X+3y=1 and -3x-3y=-15

1 answer:

3 0

$x+3y=1\\ -3x-3y=-15\\ add\quad the\quad equ.\\ (x+3y)+(-3x-3y)=1-15\\ x-3x+3y-3y=-14\\ -2x=-14\\ x=\frac { -14 }{ -2 } \\ x=7\\ Let's\quad rewrite\quad the\quad equ.\\ 7+3y=1\\ 3y=1-7\\ 3y=-6\\ y=\frac { -6 }{ 3 } \\ y=-2$

You might be interested in

Math, yes I don't know if I got it right

olga nikolaevna [1]

Answer:

4*(n)^2

Step-by-step explanation:

8 0

3 years ago

Read 2 more answers

If Sarah is 24 years younger than her mother and if the sum of their ages is 68, how old is Sarah?

irina [24]

Use subtraction the answer is 44

4 0

3 years ago

What is the sum of six times a number and 25

mina [271]

six times a number: 6(x)

The sum of 6(x) and 25: 6x + 25

6x + 25 is your expression.

hope this helps

7 0

3 years ago

Read 2 more answers

Can someone explain to me the steps how they got 2 √4^2+2x-3-2 from this question…

Naddik [55]

Step-by-step explanation:

with your square root symbol I never know what is inside the square root and what is possibly outside.

so, I can only guess and see what comes close.

f(x) = 2x² + x - 1

g(x) = sqrt(2x - 1) ??? is that so ?

h(x) = -2

2g(f(x)) + h(x)

g(f(x)) means that the whole f(x) expression is used as x in g(x).

the whole combined function is then

2×sqrt(2(2x² + x - 1) - 1) - 2

2×sqrt(4x² + 2x - 2 - 1) - 2

2×sqrt(4x² + 2x - 3) - 2

and if I am not mistaken, then this is the solution you mentioned at the beginning (if I try to read between the typos and missing info).

this is how people get to this.

do you understand it now ? or is there still something unclear ?

6 0

2 years ago

A forester studying the effects of fertilization on certain pine forests in the Southeast is interested in estimating the averag

ahrayia [7]

Answer:

$P(-2 \leq \bar X -\mu \leq 2)$

If we divide both sides by $\frac{\sigma}{\sqrt{n}}$ we got:

$P(\frac{-2}{\frac{4}{\sqrt{9}}}\leq Z \leq \frac{2}{\frac{4}{\sqrt{9}}})$

And we can use the normal distribution table or excel to find the probabilites and we got:

$P(-1.5 \leq Z \leq 1.5)= P(Z$ Step-by-step explanation:

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".

Solution to the problem

Let X the random variable that represent the area of a population, and for this case we know the distribution for X is given by:

$X \sim N(M,4)$