I dont get this problem

If f(x) = 2x - 6 and g(x) = 3x + 9, find (f - g)(x). a. (f-g)(x) = x + 15 o o b. (f- g)(x) = -x - 15 o c. (f- g)(x) = 5x + 3 o d. (f- g)(x) = -x+3 submit

The ksp expression for the system pbcl2(s) pb+2(aq) + 2 cl-(aq) is: [pbc12][pb+2][2cl-] [pb+2][cl-]2 [pb+2][2cl-]2 [pbcl2][pb+2][cl-]2 [pb+2][2cl-]2[pbcl2]

The sum of two numbers is 12 and their difference is 18 what are the two numbers