75 inches to centimetres

Find dy/dx using implicit differentiation ln(20+e^xy)=y

50 will mark show all use the linear combination method to solve the system of equations. explain each step of your solution. if steps are not explained, you will not receive credit for that step. 2x+9y= -26 -3x-7y=13

Where would an imaginary line need to be drawn to reflect across an axis of symmetry so that a regular pentagon can carry onto itself