If Friday is x, then Saturday is 150 + x. The number of people on Sunday then is (Friday + Saturday)/2, thus (x + (150 + x))/2. This then simplifies to (x + 150 + x)/2 ---> (2x + 150)/2 ---> 2x/2 + 150/2 ---> x + 75. So, Friday is x and Sunday is x + 75, to find out how many more visitors the museum have on Sunday than Friday, you subtract the two numbers. (x + 75) - x = 75.
I am not sure about this but here goes nothing: d=2.5t+2.2 is very familiar to y=mx+b y=d m=2.5 x=t b=2.2 to find a new quasion we substitute d and t into place wich equals 1=2.5(0)+b simplification and you get b=1 so your answer is d=2.5t+1
