Answer:
what is this
Step-by-step explanation:
Answer:
√
17 , 4.23 , 9/2
Step-by-step explanation:
√
17 = 4.12310562
... (about 4.1)
9/2 = 4.5
Answer:
50000000
Step-by-step explanation:
Do it yourself
Answer:
y = x*sqrt(Cx - 1)
Step-by-step explanation:
Given:
dy / dx = (x^2 + 5y^2) / 2xy
Find:
Solve the given ODE by using appropriate substitution.
Solution:
- Rewrite the given ODE:
dy/dx = 0.5(x/y) + 2.5(y/x)
- use substitution y = x*v(x)
dy/dx = v + x*dv/dx
- Combine the two equations:
v + x*dv/dx = 0.5*(1/v) + 2.5*v
x*dv/dx = 0.5*(1/v) + 1.5*v
x*dv/dx = (v^2 + 1) / 2v
-Separate variables:
(2v.dv / (v^2 + 1) = dx / x
- Integrate both sides:
Ln (v^2 + 1) = Ln(x) + C
v^2 + 1 = Cx
v = sqrt(Cx - 1)
- Back substitution:
(y/x) = sqrt(Cx - 1)
y = x*sqrt(Cx - 1)
According to the question,
Let,
"n" represent the number of miles semir walked.
"y" represent the number of miles sarah walked.
Now, according to the question,
y = 2n - 5 ........................this is your equation
Also,
the question states, each of them collect $18 in pledges for every miles walked.
Given,
Sarah collected $450
Now,
Using unitary method,
Sarah collects $18 for 1 mile
Sarah collects $1 for (1 / $18) mile
Sarah collects $450 for (1 / 18) * 450 mile
= 25 miles
So, Sarah walks 25 miles.
Now,
Taking equation,
y = 2n - 5
Since, y is the no. of miles sarah walked, we can write 25 in place of "y" So,
(25) = 2n - 5
25 + 5 = 2n
30 = 2n
30 / 2 = n
15 = n
Since, "n" is the no. of miles that semir walked, Semir walked 15 miles.
