PLEASE HELP ASAP!! LINEAR EQUATIONS

Will mark determine whether the conjecture is true or false. give a counterexample for any false conjecture. given: points r, s, and t conjecture: r, s, and t are coplanar. a) false; the points do not have to be in a straight line. b) true c) false; the points to not have to form right angles. d) false; one point may not be between the other two.

Ithink i know it but i want to be sure so can you me out ?

Solve the equation: x - 9 = -6 + 5 a. 21 b. 7 c. 14 d. 2