Lian and her younger sister Ella are 4 years apart. The sum of their ages is 20. Let l be Lian’s age in years and let e be Ella’s age in years. The system of linear equations that models the scenario is: l – 4 = e l + e = 20 How old is each sister? Lian is years old and Ella is years old.

an advantage of the standard deviation is that it increases as the dispersion of the data increases. e. the interquartile range is preferred when the data are not skewed or no have outliers. an advantage of the standard deviation is that it uses all the observations in its computation.

the answer would be 150 books

step-by-step explanation:

if you divide 300 by 2 you will get 150

answer: ♡♡♡♡♡♡♡♡♡♡

step-by-step explanation: