Tentukan jumlah10 suku pertama dari barisan bilangan berikut ini A.3+10+17+24+... b.38+33+28+23+... c.1/2+1+2+4+....

a. S10 = 10/2 (2x3 + (10-1)x7)
S10 = 5 (6 + 63)
S10 = 5 x 69
S10 = 345

b. S10 = 10/2 (2x38 + (10-1)x(-5))
S10 = 5 (76 + (-45)
S10 = 5 x 31
S10 = 155

c. S10 = 1/2 (2^10 - 1) / 2-1
S10 = 1/2 (1024 - 1)
S10 = 1/2 x 1023
S10 = 511,5