Which of the Following Systems Are Linear? Select All That $\frac { d x } { d t } = x + y , \frac { d y } { d t } = 2 t - 3 \sin t$

Multiple Choice

Which of the following systems are linear? Select all that apply.

A) $\frac { d x } { d t } = x + y , \frac { d y } { d t } = 2 t - 3 \sin t$
B) $\frac { d x } { d t } = 3.5 x + 2 y , \frac { d y } { d t } = 2 x - 5 y$
C) $\frac { d x } { d t } = x + 1 / y , \frac { d y } { d t } = 2 x e ^ { t } - 3 y$
D) $\frac { d x } { d t } = 0 , \frac { d y } { d t } = 2 \cos x - 3 y$
E) $\frac { d x } { d t } = t ^ { 2 } + 1 , \frac { d y } { d t } = 15 x - 4 y$