Question

rezolvati in r inecuatia a) -x2-2x+48<0 b) 8x2+10x-3<0

Answer 1

Pai le egalezi cu 0 si faci cu delta

Answer 2

a)-x²-2x+48<0
a=-1
b=-2
c=48
Δ=b²-4ac⇒Δ=4+192⇒Δ=196⇒√Δ=√196⇒Δ=14

x1x2=-b+-√Δ/2a
x1=2+14/-2=16/-2⇒x1=-8
x2=2-14/-2⇒-12/-2⇒x2=6
x∈{-8,6}

8x²+10x-3<0

a=8
b=10
c=-3
Δ=b²-4ac⇒100+96⇒Δ=196⇒√Δ=√196⇒Δ=14
x1x2=-b+-√Δ/2a⇒
x1=-10+14/16⇒4/16⇒x1=2/8
x2=-10-14/16⇒-24/16⇒x2=-12/8
sucees