Can someone help me with these two questions?

What is the 50th term of the sequence that begins -4, 2, 8, 14...?

What is the 20th term of the sequence that begins -3, 6, -12, 24...?

3 answers

a = -4
d = 6
T50 = a+49d = -4+49(6) = 290

a = -3
r = -2
T20 = 3(-2)^19 = -1572864
Thank you sooooooo much!!!!!!!!
thx steve you were right (thumbs up)