What an expression for “8 times x”

What is the perimeter of square abcd? units units 28 units 37 units

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?

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?