Question 255413
p^2+8p+16=0
{{{p = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}} 
p=(-8+-sqrt[8^2-4*1*16])/2*1
p=(-8+-sqrt[64-64])/2
p=(-8+-sqrt0)/2
p=(-8+-0)/2
p=-8/2
p=-4 ans.
Proof:
4^2-8*4+16=0
16-32+16=0
32-32=0
0=0