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rezolvati ecuatia bipatrata ( x*2+3)*2-11(x*2+3)+28=0

Răspuns :

( x²+3)²-11(x²+3)+28=0

x²+3=a
a²-11a+28=0
Δ=(-11)²-4×28=121-112=9
a₁=(11-√9)/2=(11-3)/2=4
a₂=(11+√9)/2=(11+3)/2=7

x²+3=4     x²=1    x₁=1   x₂=-1
x²+3=7     x²=4    x₁=2   x₂=-2