What is 2y+6x=0 in slope-intercept form?

To change this into slope-intercept form, you need to isolate your y variable.

slope-intercept form is y = mx + b

2y + 6x = 0 - - - subtract 6x

2y = - 6x - - - divide by 2

y = - 3x is your answer

Put this equation in y=mx + c form,

2y + 6x = 0

2y = - 6x + 0

y = - 3x + 0

Hence, slope intercept form of this eq. is y=-3x + 0.