Question

encontrar as raízes (x+9).(x+12)=0

Answer 1

( x+9) . (x+12) = 0
x² +12x +9x +108 
x² +21x +108
Δ= b² -4ac
Δ= 21² -4.1.108
Δ= 441 - 432
Δ= 9

x= -b +/- √Δ / 2a
x= -21 +/- √9 / 2.1
x'= -21 +3 /2
x'= -18/2
x'= -9

x''= -21 -3 /2
x''= -24/2
x''= -12

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