Giải phương trinh vi phân:
y''-2y'+y=e^x+2xe^-x, thỏa y(0)=1,y'(0)=-1

Aplane flies around trip to philadelphia it flies to philadelphia at 220 miles per hour and back home with a tailwind at 280 miles per hour if the total trip takes 6.5 hours how many miles does the plane fly round trip

Yvaries directly as x. y =90 when x=6. find y when x=13

What is y times x by? y is __ times x