Question

No 8 ma 9...
isi cara y kk...

Answer 1

8. U5 = 46
    U7 = 76   S10=?
    
    b = (76-46)/(7-5)
       = 30/2  
    b = 15
  
    U5 = a + 4b
      a = U5 - 4b
      a = 46 - 4(15)
      a = -14
 
Sn   = n/2 (2a + (n-1)b)
S10 = 10/2 (2(-14) + (10-1)15)
S10 = 5 (-28 + 135)
S10 = 535

9.   a = 30
      U2 = 65
      b = 65 - 30 = 35

Un = a + (n-1)b
U10 = 30 + (17-1)35
U10 = 30 + 560
U10 = 590