How can -6.25 + (-10.25) be expressed as the sum of it's intenger and decimal parts

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

The cost of using a service is $0.25 per min. what equation correctly represents the total cost c, in dollars, for d days of use?

Rewrite 9 log, x2 in a form that does not use exponents. 9log, x = log, x