Answer:
z = -12
Step-by-step explanation:
The given system of equations is:
xy/(x + y) = 1 ...........................(1)
xz/(x + z) = 2...........................(2)
yz/(y + z) = 3...........................(3)
From (1): x + y = xy
=> y = xy - x
y = x(y - 1)
x = y/(y - 1).......................................(4)
From (2): 2(x + z) = xz
=> 2x + 2z = xz
2x = xz - 2z
2x = z(x - 2)
z = 2x/(x - 2) ....................................(5)
From (3): 3(y + z) = yz
=> 3y + 3z = yz
3y = yz - 3z
3y = z(y - 3)
z = 3y/(y - 3)....................................(6)
Comparing (5) and (6)
2x/(x - 2) = 3y/(y - 3)
2x(y - 3) = 3y(x - 2)
2xy - 6x = 3xy - 6y
6(y - x) = xy .................................(7)
But from (1): xy = x + y
Using this in (7), we have
6(y - x) = x + y
6y - y - 6x - x = 0
5y - 7x = 0
5y = 7x
x = 5y/7................................................(8)
Using this in (4)
5y/7 = y/(y - 1)
1/(y - 1) = 5/7
(y - 1) = 7/5
y = 1 + 7/5
y = 12/5..........................................(9)
Using this in (8)
x = 5(12/5)/7 = 12/7 .......................(10)
Using (10) in (5)
z = 2x/(x - 2)
z = 2(12/7) ÷ (12/7 - 2)
= 24/7 ÷ -2/7
= 24/7 × (-7/2)
= -24/2 = -12
z = -12.
Answer:
At the 5% level, BAOI can infer that the average time to complete does not exceeds 60 hours.
Step-by-step explanation:
From the question we are told that
The population mean is 
The sample size is 
The sample mean is 
The standard deviation is 
The null hypothesis is 
The alternative 
Here we would assume the level of significance of this test to be

Next we will obtain the critical value of the level of significance from the normal distribution table, the value is 
Generally the test statistics is mathematically represented as

substituting values


Looking at the value of t and
we see that
hence we fail to reject the null hypothesis
This means that there no sufficient evidence to conclude that it takes more than 60 hours to complete the course
So
At the 5% level, BAOI can infer that the average time to complete does not exceeds 60 hours.
Answer:
The value of x for the given expression is
Step-by-step explanation:
Given as :
The statement is , three fourths times x plus five fourths equals four times x
So,
× x +
= 4 × x
<u>Now, rearranging the equation</u>
i.e 4 x -
× x =
Or, 4 x -
=
Or,
=
Or,
=
Or, 13 x =
× 4
Or, 13 x = 5
∴ x = 
Hence, The value of x for the given expression is
Answer
Answer:
$(55-3m) is the amount of money she has left
Step-by-step explanation:
In this question, we are asked to give an expression to represent how much money was left after Sarah had bought some certain stuffs at some prices using the money she received at her birthday.
Firstly, we identify that the total amount of money she has to spend is $55.
Now let’s project her total spendings. She bought 3 shirts with each shirt costing $m.
The total amount spent on the shirts is thus; 3 * $m = $3m
The amount of money she has left is the difference.
Mathematically, this is equal to $55 - $3m
Answer:115 apex
Step-by-step explanation: