Question

Rezolva in multimea R si determina ce tip de numere rationale sau irationale

a) 2,5(x-4)-6x=3-x

b)x²-3x-10=0

va rog mai rapid

Answer 1

a)2.5(x-4)-6x=3-x⇒
2.5x-10-6x=3-x⇒2.5x-6x+x=10+3⇒-2.5x=13⇒x=13/-2.5⇒x=-5.2

b)x²-3x-10=0
a=1
b=-3
c=-10
Δ=b²-4ac⇒Δ=(-3)²-4×1×(10)⇒Δ=9+40⇒Δ=49⇒√Δ=√49⇒Δ=7
x1x2=-b+-√Δ/2a⇒
x1=3+7/2⇒10/2⇒x1=5
x2=3-7/2⇒-4/2⇒x2=-2
succes