All categories

2 years ago

XY=4n+3,YZ=2n-7,XZ=22

1 answer:

7 0

Choose one of the equations, then try and rewrite in terms of 1 Unknown, eg I've chosen XZ= 22 and am going to write it in terms of X

XZ = 22
Z = 22/X (this is writing Z in terms of X)
So... X(22/X)= 22
22/X=22X
22 = 22X^2 (* ^2 is to the power 2)
Therefore X = 1
And Z= 22

Use this to solve the remaining equations

1xY = 4n + 3
22Y= 2n - 7
Then rearrange and do simultaneous equations

22Y - 66 = 88n
22Y + 7 = 2n
-73 = 86n
n = -73/86

It is very very likely that I have made a mistake somewhere here given the strange number I have for n but I spent far too long on this not to post it ahaha, even if the numbers are incorrect this is the general method I would follow

You might be interested in

the time taken by a student to the university has been shown to be normally distributed with mean of 16 minutes and standard dev

Naya [18.7K]

Answer:

a) 2.84% probability that he is late for his first lecture.

b) 5.112 days

Step-by-step explanation:

When the distribution is normal, we use the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this question, we have that:

$\mu = 16, \sigma = 2.1$

a. Find the probability that he is late for his first lecture.

This is the probability that he takes more than 20 minutes to walk, which is 1 subtracted by the pvalue of Z when X = 20. So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{20 - 16}{2.1}$

$Z = 1.905$

$Z = 1.905$ has a pvalue of 0.9716

1 - 0.9716 = 0.0284

2.84% probability that he is late for his first lecture.

b. Find the number of days per year he is likely to be late for his first lecture.

Each day, 2.84% probability that he is late for his first lecture.

Out of 180

0.0284*180 = 5.112 days

4 0

2 years ago

You’re working in a pharmacy, and are making a table to help with dosage amounts for a certain drug. The recommended dosage is 4

Sergeu [11.5K]

Answer: The children weighing 10 pounds, 15 pounds and 30 pounds require 12 teaspoons , 18 teaspoons, 36 teaspoons respectively.

Step-by-step explanation:

Given, The recommended dosage is 40 milligrams per 2.2 pounds of body weight, divided into three daily doses and taken every 8 hours.

i.e. for 1 pound of body weight required dosage per day= $\dfrac{40}{2.2}=18.18\ ml$

Each dose consist = $\dfrac{18.18}{3}=6.06\ ml$ drug.

so, 1 pound of body weight required 6.06 ml for each dose.

Then, 10 pounds of body weight require 10 x 6.06 ml drug= 60.6 ml

If 1 teaspoon = 5 ml, then 10 pounds of body weight require (60.6 ml ÷5) = 12.12 ≈12 teaspoons.

15 pounds of body weight require 15 x 6.06 ml drug= 90.9 ml

Then 15 pounds of body weight require (90.9 ml ÷5) = 18.18≈18 teaspoons.

30 pounds of body weight require 30 x 6.06 ml drug= 181.8 ml

Then 30 pounds of body weight require (181.8 ml ÷5) = 36.36 ≈ 36 teaspoons.

Hence, the children weighing 10 pounds, 15 pounds and 30 pounds require 12 teaspoons , 18 teaspoons, 36 teaspoons respectively.

7 0

2 years ago

Two vehicles are driving along a straight roadway at a constant speed. At a certain point in time, a car is 1.2 miles away from

Maurinko [17]

Answer:

The expression for the total distance between the car and the landmark in terms of the number of hours spent driving is given as follows;

1.2 = 65 × t

Where t = 1.2/65 = 0.0185 h = 66.46 seconds

Step-by-step explanation:

The parameters given are;

Distance, d between car and landmark = 1.2 miles

Speed of car = 65 miles/hr

Distance between truck and landmark = 0.7 miles

Speed of car = 55 miles/hr

The expression for the total distance between the car and the landmark as a function of time t is given as follows;

Distance, d = Speed, v × Time, t

Therefore, the expression for the total distance between the car and the landmark in terms of the number of hours spent driving is given as follows;

1.2 = 65 × t

Where t = 1.2/65 = 0.0185 h = 66.46 seconds.

7 0

2 years ago

Which action will solve the equation?. m + 20 = 9. . Add 9 to each side.. Subtract 9 from each side.. Add 20 to each side.. Subt

Kruka [31]

M + 20 = 9
u need to subtract 20 from both sides because u want to isolate m

m + 20 = 9
m + 20 - 20 = 9 - 20
m = - 11

4 0

2 years ago

Read 2 more answers

Quadrilateral WXYZ is on a coordinate plane. Segment XY is on the line x − 3y = −12, and segment WZ is on the x − 3y = −6. Which

Nostrana [21]

Answer:

Equation shown

Step-by-step explanation:

Eq(1): x-3y=-12

X=-12+3y

=-4+y

Eq(2): x-3y=-6

X=-6+3y

=-2+y

4 0

2 years ago

Read 2 more answers