Jawabanmu

2014-03-25T21:22:59+07:00
Syarat akar sama D = 0
b'' - 4ac = 0
(-p)" - 4.4.25 = 0
(-p)'' - 400 = 0
p'' - 400 = 0
p'' = 400
p = 20
2014-03-25T21:26:39+07:00
D = 0 
b²-4ac = 0
p²-4(4)(25) = 0
p²-400 = 0
p² = 400
p = √400
p = 20 atau -20

semoga membantu