Question

Rezolvati in multimea numerelor reale expresia: 4x^(2)+3x=1

Answer 1

4x^2+3x-1=0
∆=b^2-4ac
∆=3^2-4*4*(-1)
∆=9+16=>∆=25
x1=(-b+√∆)/2a=(-3+5)/2*4=>x1=2/8=1/4
x2=(-b-√∆)/2a=(-3-5)/2*4=-8/8=>x2=-1

Answer 2

4x^(2)+3x=1

[tex]\it 4x^2+3x=1 \Leftrightarrow 4x^2+3x-1=0 \Leftrightarrow 4x^2+4x-x-1=0 \Leftrightarrow \\\;\\ \Leftrightarrow 4x(x+1) -(x+1) =0 \Leftrightarrow (x+1)(4x-1)=0[/tex]

[tex]\it x+1=0 \Leftrightarrow x=-1 \\\;\\ 4x-1=0 \Leftrightarrow 4x =1 \Leftrightarrow x=\dfrac{1}{4}[/tex]