Question

Ajuta ti ma va rog dau maximu de puncte

Answer 1

x²+4x-5=0 asociem trinomul cu ecuatia de grad 2


x²+4x-5=0
Δ=b²-4ac
Δ=16-4×(-5)×1
Δ=16+20
Δ=36
x1=(-4+√Δ)/2a=(-4+6)/4=2/4=1/2
x2=(-4-6)/2=-10/2=-5

descompunem in factori trinomul de gradul 2 dupa formula:
a(X - x1)(X - x2)
 deci  a(x-x1)(x-x2)=(x-1/2)(x+5)


b)
x²+2x-15=0
Δ=b²-4ac
Δ=4+60
Δ=64
x1=(-b+√Δ)/2ac=(-2+√Δ)/2=(-2+8)/30=6/30=1/5
x2=(-b-√Δ)/2ac=(-2-√Δ)/2=(-2-8)/30=-10/30=-1/3
descompunem in factori trinomul de gradul 2 dupa formula:
a(X - x1)(X - x2)
(x-1/5)(x+1/3)

c)
x²-7x+12=0
Δ=49-48
Δ=1
x1=(7+1)/2=4
x2=(7-1)/2=3
(x-4)(x-3)