Need help to see if my answer are wrong or right before anything for all of them ?

The suare 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?

Reinel saves 30% of every pay check. his paycheck last week was 560$. how much did reniel save last week?