Classify the following differential equations as linear or nonlinear:

3x' +5x=7t^2
4x^2+2x+5tx=0

1 answer

Evidently you have not reviewed the definition of a linear DE:

A differential equation is linear if the unknown function and its derivatives appear to the power 1 (products of the unknown function and its derivatives are not allowed) and nonlinear otherwise.

So, the first above is linear, and the second is not.