The cost per foot of redwood and of pine is $3.5 and $1.5 respectively.
<h3>How to solve simultaneous equation?</h3>
let
- cost of redwood = x
- cost of pine = y
50x + 70y = 280
100x + 60y = 440
Multiply (1) by 2
100x + 140y = 560
100x + 60y = 440
subtract to eliminate x
80y = 120
y = 120/80
y = $1.5
substitute y = 1.5 into (1)
50x + 70y = 280
50x + 70(1.5) = 280
50x + 105 = 280
50x = 280 - 105
50x = 175
x = 175 / 50
x = $3.5
Learn more about equation:
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Answer:
Hi,
Step-by-step explanation:
PR²=PQ²+QR²-2*PQ*QR*cos(51°)
=15²+12²-2*15*12*cos(51°)
=142,444659....
PR=11.9350...
PQ²=QR²+PR²-2*QR*PR*cos(R)
cos(R)=(12²+142.444...-15²)/(2*12*11.9350...)=0,21451112....
angle R=77,61315...°≈77.6°
angle P=180°-51°-77.6°≈51,4°
Jordan have $286 in his account after 1 year.
<u>Solution:</u>
Given data:
Principal (P) = $275.00
Rate of interest (R) = 4%
Time (T) = 1 year
<u>Let us first calculate the simple interest.</u>
Simple Interest Formula:

Substitute the given values in the simple interest formula.


Simple interest = $11
<u>Calculating the amount in account after 1 year:</u>
Amount = Principle + Simple Interest
= $275.00 + $11
Amount = $286
Hence Jordan have $286 in his account after 1 year.
Using the <u>normal distribution and the central limit theorem</u>, it is found that there is a 0.1635 = 16.35% probability of a sample result with 68% or fewer returns prior to the third day.
In a normal distribution with mean
and standard deviation
, the z-score of a measure X is given by:

- It 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, which is the percentile of X.
- By the Central Limit Theorem, for a proportion p in a sample of size n, the sampling distribution of sample proportions has mean
and standard error 
In this problem:
- Sample of 500 customers, hence
.
- Amazon believes that the proportion is of 70%, hence

The <u>mean and the standard error</u> are given by:


The probability is the <u>p-value of Z when X = 0.68</u>, hence:

By the Central Limit Theorem



has a p-value of 0.1635.
0.1635 = 16.35% probability of a sample result with 68% or fewer returns prior to the third day.
A similar problem is given at brainly.com/question/25735688
5n² - 8n - 21 → (5)(- 21) = -105 (find 2 numbers whose product is 105 and sum is -8)
= 5n² - 15n + 7n - 21
= 5n(n - 3) + 7(n - 3)
= (5n + 7)(n - 3)
*****************************************************
6n² + 53n - 79 → (6)( -79) = -474 (find 2 numbers whose product is -474 and sum is 53) DOES NOT EXIST! only factors are: (1, 474) (2, 237) (3, 158) (6, 79)
= Prime
*******************************************************
4n² - 25 (this is the difference of two squares)
= √(4n²) +/- √(25)
= 2n +/- 5
= (2n + 5)(2n - 5)