k²+2/5k+1/25 tolong dengan cara

dikalikan 25
25k^2 + 10k + 1
dicari nilai k
1/25(k+5)(k+5)
1/25k + 1/5 = 0
k = -1/5 ÷ 1/25
k = -1/5 × 25/1
k = -5
atau
k+5 = 0
k = -5