Choose the equivalent system of linear equations that will produce the same solution as the one given below.

4x - y = -11
2x + 3y = 5

a) -4x - 9y = -19
-10y = -30

b) 4x + 3y = 5
2y = -6

c) 7x - 3y = -11
9x = -6

d) 12x - 3y = -33
14x = -28

Having a hard time understanding this question (see attachment).

Serena is making an experiment. for that, she needs 20 grams of a 52% solution of salt. she has two large bottles of salt water: one with 40% and the other with 70% of salt in them. how much of each must she use to make the solution she needs? i am in need of

Select the correct answer from each drop-down menu. james needs to clock a minimum of 9 hours per day at work. the data set records his daily work hours, which vary between 9 hours and 12 hours, for a certain number of days. {9, 9.5, 10, 10.5, 10.5, 11, 11, 11.5, 11.5, 11.5, 12, 12}. the median number of hours james worked is . the skew of the distribution is