How do I solve for this...?

Nine more than four times a number is the same as one less than twice the number. find the number?

The brain volumes (cm cubed) of 50 brains vary from a low of 904 cm cubed to a high of 1488 cm cubed. use the range rule of thumb to estimate the standard deviation s and compare the result to the exact standard deviation of 175.5 cm cubed, assuming the estimate is accurate if it is within 15 cm cubed

James was playing a game with his friends. he won 35 points. then he lost 15, lost 40 and won 55. how did he come out