Answer:
Step-by-step explanation:
If the equations are true, they can be solved simultaneously.
Consider 2x-10y=-1 as Eq1 and 5x+6y=4 as Eq2
Multiplying Eq1 with 3 and Eq2 with 5 we get,
6x-30y=-3 -- Eq3 and 25x+30y=20 -- Eq4
Adding Eq3 and Eq4,
31x=17 Therefore, x=17/31
Plugin x=17/31 in Eq3,
6(17/31)-30y=-3 --- y=13/62
Plug In values of x and y in 7x-4y we get,
7(17/31)-4(13/62) = 3
So the value of 7x-4y = 3.
Answer:
the answer is about 8 cuz the answer shows 7.12 if you divide mentally
The answer is 138 million.
Step 1. Calculate the growth rate.
Step 2. Calculate the population number in 2014.
We will use the formula for exponential growth:
A = P * eⁿˣ
where:
A - the final amount (value)
P - the initial amount (value)
e - the mathematical constant (e ≈ 2.72)
n - the growth rate
x - the time
Step 1:
A = 120 million = 120 000 000
P = 114 million = 114 000 000
n = ?
x = 1997 - 1991 = 6
Therefore:

Logarithm both sides of the equation:

Step 2:
Now when we know the growth rate, it is easy to estimate the population in 2014
A = ?
P = 120 000 000
n = 0.0083
t = 2014 - 1997 = 17

Thus, the population will be 138 million in 2014
Answer:
Step-by-step explanation:
Let M be the heights of men in the United States and W be the heights of women in the United States
Given that M is N(69.1, 2.9) and W (63.7, 2.7)
For a husband and wife we have average height as
=Z (say)
![Mean =E(z) = \frac{1}{2} [E(M)+E(W)] = 66.4 inches](https://tex.z-dn.net/?f=Mean%20%3DE%28z%29%20%3D%20%5Cfrac%7B1%7D%7B2%7D%20%5BE%28M%29%2BE%28W%29%5D%20%3D%2066.4%20inches)
Var (Z) =![Var (\frac{x+y}{2} )=\frac{1}{4}[Var(x)+ Var(y)+2 cov (x,y)]\\](https://tex.z-dn.net/?f=Var%20%28%5Cfrac%7Bx%2By%7D%7B2%7D%20%29%3D%5Cfrac%7B1%7D%7B4%7D%5BVar%28x%29%2B%20Var%28y%29%2B2%20cov%20%28x%2Cy%29%5D%5C%5C)
=![0.25[2.9^2+2.7^2+2*r*sx*sy]\\= 0.25(20.398)\\=5.0995](https://tex.z-dn.net/?f=0.25%5B2.9%5E2%2B2.7%5E2%2B2%2Ar%2Asx%2Asy%5D%5C%5C%3D%200.25%2820.398%29%5C%5C%3D5.0995)
Mean = 66.4" and std dev = 2.258
Answer:
C) 42/7 = n
Step-by-step explanation:
A week is 7 days, so, to figure out how many cups of dog food she gives her dog daily, we would need to do her weekly amount, 42, divided by 7, the amount of days in a week :)