What is the contrapositive of "if it is tuesday then marie has soccer practice?

What is another way to express 36 +32

The square root of 9x plus 7 plus the square rot of 2x equall to 7

The distribution of the amount of money spent by students for textbooks in a semester is approximately normal in shape with a mean of $235 and a standard deviation of $20. according to the standard deviation rule, how much did almost all (99.7%) of the students spend on textbooks in a semester?