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rezolvati in z ecuatia 4x la a doua -1= 1-7x
va rog multtttttttttt dau coroana


Răspuns :

4x²-1=1-7x
4x²-1-1+7x=0
4x²+7x-2=0
Δ=b²-4ac=>Δ=49+32=81=>√Δ=9
x₁=(-b-√Δ)/2a=(-7-9)/8=>x₁=(-16)/8=>x₁=(-2)∈Z
x
₂=(-b+√Δ)2a=(-7+9)/8=>x₂=2/8=>x₂=0,25∉Z