tlong bnatuannya plis pakai caranya

Semoga dapat membantu

U6 = 17
U10 = 33
S30?
U6 = a + 5b = 17
U10 = a + 9b = 33
eliminasi
a + 9b = 33
a + 5b = 17
_________
      4b = 16
        b = 4
a + 5(4) = 17
a + 20 = 17
a = -3
S30 = 30/2 (2(-3) + (30 - 1)4)
       = 15 x (-6 + 116)
       = 1650