Find the value of x ?

Sara needs to take a taxi to get to the movies the taxi charges $4.00 for the first mile and then $2.75 for each mile after that if the total charge is $20.50 then how far was sara’s taxi ride to the movie

According to the general equation for conditional probability if p(anb)=3/7 and p(b)=7/8 what is p(a i b)

If on=8x-8,lm=7x+4,nm=x-5,and ol=3y-6