These two questions are 12U Calculus and Vectors questions (vectors specifically). It's concerning linear combinations of vectors. May those who answer please explain with words, their process/thinking of how to solve the problem. Thank you very much to anyone helping me with this!

15. The vectors a and b span R2. What values of m and n will make the following statement true: (m - 2)a = (n + 3)b? Explain your reasoning. 17. The vectors a and b span R2. For what values of m is it true that (m- + 2m - 3)a + (m + m - 6)b = 0? Explain your reasoning