All categories

3 years ago

Solve the system of equations.

Mathematics

1 answer:

Alex3 years ago

7 0

Solve x+3y=-1 for x:

Add -3 to both sides

x+3y+-3y=-1+-3y

x=-3y-1

Substitute -3y-1 for x in 2x+2y=6

2x+2y=6

2(-3y-1)+2y=6

Simplify both sides of the equation

-4y-2=6

Add 2 both sides

-4y-2+2=6+2

-4y=8

Divide both sides by -4

-4y/-4=8/-4

y=-2

Substitute -2 for y in x=-3y-1

x=-3y-1

x= (-3)(-2)-1

Simplify both sides of the equation

x=5

Answer : D

x=5 and y=-2

I hope that's help and have a great night !

You might be interested in

A study showed that 25% of the students drive themselves to school. Based on the suggested probability, in a class of 18 student

Gwar [14]

Answer:

B) 0.283

Step-by-step explanation:

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

25% of the students drive themselves to school.

This means that $p = 0.25$

Class of 18 students

This means that $n = 18$

What would be the probability that at least 6 students drive themselves to school?

This is

$P(X \geq 6) = 1 - P(X < 6)$

In which

$P(X < 6) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) + P(X = 5)$

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 0) = C_{15,0}.(0.25)^{0}.(0.75)^{18} = 0.006$

$P(X = 1) = C_{15,1}.(0.25)^{1}.(0.75)^{17} = 0.034$

$P(X = 2) = C_{15,2}.(0.25)^{2}.(0.75)^{16} = 0.096$

$P(X = 3) = C_{15,3}.(0.25)^{3}.(0.75)^{15} = 0.17$

$P(X = 4) = C_{15,4}.(0.25)^{4}.(0.75)^{14} = 0.213$

$P(X = 5) = C_{15,5}.(0.25)^{5}.(0.75)^{13} = 0.199$

$P(X < 6) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) + P(X = 5) = 0.006 + 0.034 + 0.096 + 0.17 + 0.213 + 0.199 = 0.718$

$P(X \geq 6) = 1 - P(X < 6) = 1 - 0.718 = 0.282$

Closest option is B, just a small rounding difference.

4 0

3 years ago

A decagon with points labeled a through j clockwise. point a is the top left point. if this regular decagon is rotated countercl

serg [7]

The e vertex of the decagon will be in the top position after rotating it counterclockwise by 3 times the smallest angle of rotation.

Which vertex will be in the top position of the regular decagon?

A regular decagon has 10 sides of equal lengths with points labeled 'a' through 'j' clockwise. It is given that the point a is the top-left point. Hence, the the vertex which is in the the top position currently is 'b'.

Now, the smallest angle of rotation will be the angle between the two sides of the decagon.

In the first rotation by the smallest angle in counterclockwise direction, point 'c' will come to the top position. In the second rotation by the smallest angle in counterclockwise direction, point 'd' point will become the top most vertex. Finally, after the third similar rotation, 'e' vertex will be in the top position of the decagon. (Refer the attached diagram)

Learn more about decagon here:

brainly.com/question/27314677

#SPJ4

5 0

2 years ago

Read 2 more answers

I need help, my teacher didnt teach up this

nlexa [21]

Answer:

The volume is <u>1539.38</u>

Step-by-step explanation:

7 0

3 years ago

Read 2 more answers

Find all zeros of <br>f(x)= x^3 + 3x^2 − 3x − 1

PSYCHO15rus [73]

F(1) = 1^3 + 3(1)^1 - 3 - 1 = 1 + 3 - 3 - 1 = 0

so one zero is x = 1, and x-1 is a factor

dividing f(x) by x - 1 gives x^2 + 4x + 1

x = [-4 +/- sqrt (16 - 4)] / 2

x = -0.27, -3.73

zeroes are 1 , -0.27 and -3.73 Answer

4 0

3 years ago

I am a geometric solid I have two surfaces one of my surfaces is formed by a circle the other surface is curved what am I

kirill115 [55]

Cylender Hope this helps

8 0

3 years ago

Read 2 more answers