Multiply the first equation with (-1)
you should get this
-6r + 3t = -6
6r + 8t = -16
start to eliminate
11t = -22
divide by 11
t = -2
substitute
6r - 3(-2) = 6
6r + 6 = 6
6r = 6 - 6
6r = 0
r=0
Standard formula for arithmetic sequence:
an = a0 + d(n-1)
if we use the two terms given, setting a12 as starting term and a45 as the end term an.
170 = 38 + 33d
170 - 38 = 33d
132 = 33d
132/33 = d
This is the common difference, use it to find the first term.
38 = a0 + (132/33)(12-1)
38 = a0 + (132/33)(11)
38 = a0 + 132/3
38 - 132/3 = a0
38 - 44 = a0
-6 = a0
The starting term is -6
All i got was 1 and a half months
