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Differential Equations

Question
CBSEENMA12033161

Solve:
dy over dx plus 4 straight y space equals space 5 straight x

Solution
The given differential equation is
                 dy over dx plus 4 straight y space equals space 5 straight x
Comparing it with dy over dx plus straight P space straight y space equals space straight Q comma we get,
                    P = 4,   Q = 5x
integral straight P space dx space equals space integral 4 space dx space equals space 4 straight x
      straight I. straight F. space equals space straight e to the power of integral straight P space dx end exponent space equals space straight e to the power of 4 straight x end exponent
Solution of given differential equation is
                  ye to the power of integral straight P space dx end exponent space equals space integral space straight Q space straight e to the power of integral space straight P space dx end exponent dx space plus space straight c
or          ye to the power of 4 straight x end exponent space equals space integral 5 space straight x space straight e to the power of 4 straight x end exponent dx space plus straight c
or space space space space space straight y space straight e to the power of 4 straight x end exponent space equals space 5 space integral straight x space straight e to the power of 4 straight x end exponent dx plus straight c
or space space space space straight y space straight e to the power of 4 straight x end exponent space equals space 5 space open square brackets straight x space straight e to the power of 4 straight x end exponent over 4 minus space integral 1. space straight e to the power of 4 straight x end exponent over 4 dx close square brackets plus straight c
or space space space space straight y space straight e to the power of 4 straight x end exponent space equals space 5 over 4 straight x space straight e to the power of 4 straight x end exponent minus 5 over 4 integral straight e to the power of 4 straight x end exponent dx space plus space straight c
or space space space straight y space straight e to the power of 4 straight x end exponent space equals space 5 over 4 straight x space straight e to the power of 4 straight x end exponent space minus space 5 over 4. space straight e to the power of 4 straight x end exponent over 4 plus straight c
therefore space space space space space space space space straight y space equals space 5 over 4 straight x minus 5 over 16 plus ce to the power of negative 4 straight x end exponent
is required solution. 

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