Tolonggggggggggggggg​

Jawab:

Penjelasan dengan langkah-langkah:

soal

4 + 9 + 14 + . . . + (5n – 1) = 1/2 n (5n + 3)

p(k+1) = P(k) + U(k+1)

1/2 (k+1) {5(k+1) + 3 } =  1/2 (k)(5k+ 3) +  5 (k+1) – 1

1/2 (k+1)  (5k +8) = 1/2 (5k² + 3k)  + 5k+ 4

1/2 (k+1)  (5k +8) = 1/2 (5k² + 3k)  + 1/2 (10k+ 8)

1/2 (k+1)  (5k +8) = 1/2 { (5k² + 3k + 10k+ 8)

1/2 (k+1)  (5k +8) = 1/2 { (5k² + 13k + 8)

1/2 (k+1)  (5k +8) =  1/2 (k+1)  (5k +8)

kiri  = kanan (terbukti)