Question

Jumlah keliapatan 5 antara 100 dan 300?

Answer 1

u1 = a = 105
b = 5
Un = 295
jawabnnya
Un =a + (n-1)b
295= 105 + (n-1)5
295 = 105 + 5n – 5
295 = 100 + 5n
295-100= 5n
195 = 5n
195/5 = n
   39 = n

Sn = n/2 (2a + (n-1)b )
S49 = 39/2 (2 x 105 + ( 39-1)5)
       = 39/2 ( 210 + 190 )
       = 39/2 x 400
       = 39 x 200
       = 7800


jawabannya 7800