Question

Cui ii pot cere ajutorul pt rezolvarea celor doua ecuații încercuite?

Answer 1

2x²+7x-4=0

a=2;b=7;c=-4

Δ=b²-4ac=7²-4*2*(-4)=49+32=81>0

x₁₂=(-b±√Δ)/2a=(-7±√81)/2*2=(-7±9)/4

x₁=(-7+9)/4=2/4=1/2

x₂=(-7-9)/4=-16/4=-4

S={-4,1/2}

2x²+10x=6(x+1)|:2

x²+5x=3(x+1)

x²+5x=3x+3

x²+2x-3=0

a=1;b=2;c=-3

Δ=b²-4ac=2²-4*1*(-3)=4+12=16>0

x₁₂=(-b±√Δ)/2a=(-2±√16)/2*1=(-2±4)/2=-1±2

x₁=-1+2=1

x₂=-1-2=-3

S={-3;1}

Answer 2

1. 2x^2+7x-4=0

2x^2+8x-x-4=0

2x×(x+4)-(x+4)=0

(x+4)×(2x-1)=0

x+4=0

2x-1=0 =>

x=-4 | x=1/2 ( soluțiile finale )

2. 2x^2+10x=6(x+1)

x^2+5x=3(x+1)

x^2+5x=3x+3

x^2+5x-3x-3=0

x^2+2x-3=0

x^2+3x-x-3=0

x×(x+3)-(x+3)=0

(x+3)×(x-1)=0

=>

x+3=0

x-1=0

x=-3 | x=1 (Soluții finale )