Answer:
y = 56/3
Step-by-step explanation:
We need to write equations to solve
Let the two numbers be x and y
The sum is 56
x+y = 56
The first number is 2 times greater than the second number.
x = 2*y
Substitute this into the first equation
x+y = 56
2y+y=56
3y = 56
y = 56/3
Answer:

Step-by-step explanation:

This is a homogeneous linear equation. So, assume a solution will be proportional to:

Now, substitute
into the differential equation:

Using the characteristic equation:

Factor out 

Where:

Therefore the zeros must come from the polynomial:

Solving for
:

These roots give the next solutions:

Where
and
are arbitrary constants. Now, the general solution is the sum of the previous solutions:

Using Euler's identity:


Redefine:

Since these are arbitrary constants

Now, let's find its derivative in order to find
and 

Evaluating
:

Evaluating
:

Finally, the solution is given by:

The easiest way to solve this is by elimination.
3x - y = 6
6x + y = 21
Since you have a negative and positive y with the same coefficients (1), they cancel, and you add the other terms so it would look like:
9x = 27
Then solving for x leaves you with x = 3
Then you take the x value of three and plug it into to either of the equations, so
3(3) - y = 6
9 - y = 6
subtracting 9
-y = -3
then dividing by -1
y = 3
so the solution is x = 3 y = 3 or (3,3)
If m =2 insert m so 4+4-3+5
answer is 5