All categories

3 years ago

9th grade math help me please and thank you sosomuch

Mathematics

1 answer:

Varvara68 [4.7K]3 years ago

7 0

Answer:

The system is consistent; it has one solution ⇒ D

Step-by-step explanation:

A consistent system of equations has at least one solution

The consistent independent system has exactly 1 solution

The consistent dependent system has infinitely many solutions

An inconsistent system has no solution

In the system of equations ax + by = c and dx + ey = f, if

a = d, b = e, and c = f, then the system is consistent dependent and has infinitely many solutions
a = d, b = e, and c ≠ f, then the system is inconsistent and has no solution
a ≠ d, and/or b ≠ e, and/or c ≠ f, then the system is consistent independent and has exactly one solution

In the given system of equations

∵ -2y + 2x = 3 ⇒ (1)

∵ -5y + 5x = 12 ⇒ (2)

→ By comparing equations (1) and (2)

∵ -2 ≠ -5

∵ 2 ≠ 5

∵ 3 ≠ 12

→ By using the 3rd rule above

∴ The system is consistent independent and has exactly one solution

∴ The system is consistent; it has one solution

You might be interested in

3) A number between 0 and 1, expressed as one number over another, is called a _ _ _ _ _ _ _ _.

Bond [772]

If you write a number over another number, it's called a FRACTION

5 0

3 years ago

Read 2 more answers

An automotive manufacturer wants to know the proportion of new car buyers who prefer foreign cars over domestic. Step 2 of 2 : S

ziro4ka [17]

Answer:

The 85% onfidence interval for the population proportion of new car buyers who prefer foreign cars over domestic cars is (0.151, 0.205).

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence level of $1-\alpha$ , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which

z is the zscore that has a pvalue of $1 - \frac{\alpha}{2}$ .

For this problem, we have that:

Sample of 421 new car buyers, 75 preferred foreign cars. So $n = 421, \pi = \frac{75}{421} = 0.178$

85% confidence level

So $\alpha = 0.15$ , z is the value of Z that has a pvalue of $1 - \frac{0.15}{2} = 0.925$ , so $Z = 1.44$ .

The lower limit of this interval is:

$\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.178 - 1.44\sqrt{\frac{0.178*0.822}{421}} = 0.151$

The upper limit of this interval is:

$\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.178 + 1.44\sqrt{\frac{0.178*0.822}{421}} = 0.205$

The 85% onfidence interval for the population proportion of new car buyers who prefer foreign cars over domestic cars is (0.151, 0.205).

8 0

2 years ago

What is 26555 x 3? Brainliest will be given!!!!!

Leona [35]

Answer:

79665

Step-by-step explanation:

26555 + 26555 is 53110 then add 26555 again at it equals 79665

6 0

3 years ago

Read 2 more answers

Is x+6 an example of a ratio

serg [7]

A ratio is is statement of how two nummber's compare

5 0

3 years ago

Can some show the steps and the answer please I really need help tell me how you get it and the answer

Lana71 [14]

Answer:

Step-by-step explanation:

so this is about triangles.. sooo the following is a bit of helpful reminders that I keep on my computer to help me remember how to fit the trig functions to triangles.. I strongly suggest you copy it and keep it where you can look at it often.

Use SOH CAH TOA to recall how the trig functions fit on a triangle

SOH: Sin(Ф)= Opp / Hyp

CAH: Cos(Ф)= Adj / Hyp

TOA: Tan(Ф) = Opp / Adj

I use this anytime I run into triangles or need some help with sin or cos

now the problem , 3 ladder 10, 12, & 15 feet. Alex wants to get to 8 feet.

the problems is also telling you that you can use t..... and then , the words are cut off.. but I know they were going to say Tan ... next.. :P

b/c Tan is how you figure out problems with the adjacent side and the opposite side. like this problem. Look at TOA above. use that to recall how the parts fit in the formula

Tan(∅) = Opp / Adj

they give us the Opp side of 8 feet in the problem

then they also tell us the Hyp of the triangle which is each of the ladders length. Then they ask us what is the Adj sides length?

So we also need to solve the triangle with the know hyp (ladder length).. uggg, this problem is long. Then we can solve the dist. from the wall or Adj side length.

it's two steps, if you want to think of it that way. You're supposed to be pretty confident with trig functions. I'm guessing this is a trig class.. right?

let's solve for the 3 different angles that the ladders make , each going to 8 feel. Obviously, nobody would really do this with a ladder they would just lean it against the wall . and if it's taller than where they want to climb, they would just go up part way. so anyway, find the 3 different angles.

look above to see which formula to use.

I like SOH b/c it seems to have all the pieces of the triangle we want to work with.

ladder 1 ( 10')

Sin(∅) = Opp / Hyp

Sin(∅) = 8 / 10

∅ = arcSin (4/5)

[ first, yes, I just reduced the fraction, then I did the arcSin on both sides, I think you might know how to do that already ? ]

∅ = 53.13010 °

( yes, I used my calculator to find that, calculators are okay to use when figuring out non standard angles )

ladder 2 (12')

Sin(∅) = 8/12

∅ = arcSin (2/3)

∅ = 41.81031°

ladder 3 (15')

Sin(∅) = 8/15

∅ = arcSin (8/15)

∅ = 32.230952°

now use our Tan function to find the Adjacent side which is the distance from the wall

Tan(∅)= Opp / Adj

Adj = Opp / Tan(∅)

( I did some quick algebra to move the side we want to solve for, now plug and chug all 3 angles )

ladder 1

Adj = 8 / Tan(53.13010)

Adj = 6.0000005

ladder 2

Adj = 8 / Tan(41.81031)

Adj = 8.94427

ladder 3

Adj = 8 / Tan(32.230952)

Adj = 12.688577

so the 10' ladder is 6 feet from the wall

the 12' ladder is 8.9 feet from the wall

the 15 foot ladder is 12.7 feet from the wall.

I really don't think that 15' ladder is going to stay on the wall.. if Alex climbs it... it's way way too far out... it will just fall straight down the wall :/ Maybe another math problem for the forces involved :P

5 0

2 years ago