A linear sequence is as follows: a+b, a+3b, a+5b .... The 2nd term is equal to 15. The 6th term is 47. What is the value of a? What is the value of b? Show your working.
a+3b = 15, a+11b=47 , use simultaneous equations to get 8b = 32 therefore b=4 and a=3.
