Question

resolva as equacoes do 2 grau
1) X2-4X-5=0
2) -X2+6X-5=0
3) 3X2-7X+2=0
4) 4X2-12+9=0​

Answer 1

Resposta:

1.x²-4x-5=0 2.-x²+6x-5=0

x²+x-5x-5=0 x²-6x+5=0

x.(x+1)-5(x+1)=0 x²-x-5x+5=0

(x+1).(x-5)=0 x.(x-1)-5(x-1)=0

x+1=0/x=-1 (x-1).(x-5)=0

x-5=0/x=5 x-1=0/x=1

x-5=0/x=5

3.3x²-7x+2=0 4.4x²-12+9=0

3x²-x-6x+2=0 (2x-3)²=0

x.(3x-1)-2(3x-1)=0 2x-3=0

(3x-1).(x-2)=0 2x=3/x=3/2

3x-1=0/3×=1/x=1/3

x-2=0/×=2