. In the problems below (just as in the lecture), the four subspaces associated to a matrix are the column space, the nullspace (or Kernel), the row space, and the left nullspace. Answer the following: (a) If a 3 × 4 matrix has rank 3, what are the dimensions of the four subspaces? (b) If a 7 × 9 matrix has rank 5, what are the dimensions of the four subspaces?

City l has a temperature of −3 °f. city m has a temperature of −7 °f. use the number line shown to answer the questions: number line from negative 8 to positive 8 in increments of 1 is shown. part a: write an inequality to compare the temperatures of the two cities. (3 points) part b: explain what the inequality means in relation to the positions of these numbers on the number line. (4 points) part c: use the number line to explain which city is warmer. (3 points)