Find dy/dx give the relation

(x^2/9)+(y^2/16)=1

Thank you!!

(x^2/9)+(y^2/16)=1 -->

2/9 x dx + y/8 dy = 0 ------->

2/9 x + y/8 dy/dx = 0 --------->

dy/dx = -16/9 x/y