Question

rezolvati in R ecuatia
a) 2x²+x-6=0
b) (x-3)(x+2)=14
Autatima va rog !!!

Answer 1

a)2x²+x-6=0
a=2
b=1
c=-6
Δ=b²-4ac
Δ=1²-4·2·(-6)=1+48=49
x₁=(-b+√Δ)/2a
x₁=(-2+7)/4=5/4
x₂=(-2-7)/4=-9/4
x∈{-9/4, 5/4}

b)(x-3)(x+2)=14
x²+2x-3x-6=14
x²-x-6-14=0
x²-x-20=0
Δ=1+80=81
x₁=(1-9)/2=-8/2=-4
x₁=-4
x₂=(1+9)/2=10/2
x₂=5
x∈{-4,5}