4x - y + z = -5
-x + y -z = 5
2x -z -1 = y

linear systems 3 variables I'm lost

James wants to promote his band on the internet. site a offers website hosting for $4.95 per month with a $49.95 startup fee. site b offers website hosting for $9.95 per month with no startup fee. for how many months would james need to keep the website for site a to be a better choice than site b? 1. define a variable for the situation. 2. write an inequality that represents the situation. 3.solve the inequality to find out how many months he needs to keep the website for site a to be less expensive than site b. 4. using words, describe how many months he needs to keep the website for site a to be less expensive than site b.

Which value of m will create a system of parallel lines with no solution? y = mx - 6 8x - 4y = 12

Acontainer holds 0.7 liters of oil and vinegar. 3/4 of the mixture is vinegar. how many liters of oil are in the container? express your answer as both a fraction and a decimal.