buktikan dengan induksi matematika. 6+8+10+12+......+(2n+4)=n(n+5) tolong bantu saya

jawab

n =1 → 1 + 1
n = k → 6+8+10+...+(2k+4) = k(k+5)
n = k + 1 → k(k+5) +  2(k+1) + 4 = (k+1)(k+1+5)
k² + 5k + 2k + 2 + 4 = (k+1)(k+6)
k² + 7k + 6 = (k+1)(k+6)
(k+1)(k+6) = (k+1)(k+6)