👤
a fost răspuns

X la a 2 - 7x- 15=3
D=b la a 2 -4ac
X1x2= -b√d/2a
Va rog ajutatima am mare nevoi

Răspuns :

MFM
X²-7X-15=3
X²-7X-18=0
Δ=b²-4ac=49+72=121
x1,x2=(-b+/-√Δ)/2a
x1,x2=(7+/- √121)/2=

x1=(7-11)/2=-4/2=-2
x2=(7+11)/2=9
Alexandravert
x²-7x-15=3=>x²-7x-15-3=0, x²-7x-18=0
a=1, b=-7, c=-18
Δ=b²-4ac
Δ=(-7)²-4*1*(-18)
Δ=49+72
Δ=121
x₁=(-b+√Δ)/2a
x₁=[-(-7)+√121]/2*1
x₁=(7+11)/2
x₁=18/2
x₁=9
x₂=(-b-√Δ)/2a
x₂=[-(-7)-√121]/2*1
x₂=(7-11)/2
x₂=-4/2
x₂=-2

Alte intrebari