If ab perpendicular to cd and the slope of ab = 1 over 2 then the slope of cd =

How do i do this using elimination 2x+3y=12 x-y=6

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

He weights of 2-pound bags of best dog food are approximately normally distributed with a given mean  and standard deviation  according to the empirical rule, what percentage of the bags will have weights within 3 standard deviations of the mean? 47.5%68%95%99.7%