What expressions are equivalent to to -56 + 28

Given the following sampling distribution of one mean with a sample size 49, from a normally distributed population,find the population standard deviation, o.79828588912497

Find the value of p for which the polynomial 3x^3 -x^2 + px +1 is exactly divisible by x-1, hence factorise the polynomial

Abus travels 36 miles in 45 minutes. enter the number of miles the bus travels in 60 minutes at this rate.