Answer:
k = 30, 
Step-by-step explanation:
Since
is a solution, then it must satisfy the differential equation. So, we calculate the derivatives and replace the value in the equation. We have that

Then, replacing the derivatives in the equation we have:

Since
is a positive function, we have that
.
Now, consider a general solution
, then, by calculating the derivatives and replacing them in the equation, we get

We already know that r=5 is a solution of the equation, then we can divide the polynomial by the factor (r-5) to the get the other solution. If we do so, we get that (r-6)=0. So the other solution is r=6.
Therefore, the general solution is

Answer:
72°
Step-by-step explanation:
Let the 2 equal angles be x then the third angle is x + 18
The sum of the 3 angles in a triangle = 180°, thus
x + x + x + 18 = 180, that is
3x + 18 = 180 ( subtract 18 from both sides )
3x = 162 ( divide both sides by 3 )
x = 54
Hence
the largest angle = x + 18 = 54 + 18 = 72°