Which of the following subsets of the vector space r 3 are subspaces of r 3 ?

(i) the set of all vectors v =   x y z   with the property 2xyz = 0.

(ii) the set of all the solutions of the equation x − 5y + 2z = 0.

(iii) the set of all solutions for the system   2 3 2 5 2 8 −1 1 3     x y z   =   0 0 0  .

(iv) the set of all the solutions of the equation x + 3y = 2z + 1.

Which product is positive a is 2/5 -8/9 -1/3 -2/7 b is -2/5 8/9 -1/3 -2/7 c is 2/5 8/9 1/3 -2/7 d is -2/5 -8/9 1/3 2/7

The table above shows approximate conversions from gallons to liters. what is the value of x?

According to the 2008 u.s. census, california had a population of approximately 4 × 10^7 people and florida had a population of approximately 2 × 10^7 people. which of the following is true? a. the population of florida was approximately two times the population of california. b. the population of florida was approximately twenty times the population of california. c. the population of california was approximately twenty times the population of florida. d. the population of california was approximately two times the population of florida.