$y''+x'-x+y = \sin t$
$x''+y'-x+y = e^t$
Any ideas?
$y''+x'-x+y = \sin t$
$x''+y'-x+y = e^t$
Any ideas?
Subtract the second equation from the first equation to get: $(y-x)''-(y-x)'=sin t-e^t$ Let z=y-x Solve this to get z then substitute y=x+z in one of the equations you gave.