Estimate the sum or difference. 1/2-1/3=

Identify a1 and r for the geometric sequence an= -256(-1/4) n-1

Find the roots of the polynomial function f(x) = x^3 + 2x^2 + x

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?