Question

ME AJUDEMMMMM
Resolva as equaçoes do 2° grau a seguir:

a)(x + 9) . (x -5)=0
b)(x - 5) . (x - 6)=0
c) x(x + 2)= 2x + 36
 d) $\frac{y^2}{4} + \frac{y}{3} = \frac{y}{2}$ 

Answer 1

Desenvolva:
a)(x+9)*(x-5)=0 ⇒ x²-5x+9x-45=0 ⇒ x²+4x-45=0

Agora aplique Baskara, e ache as raízes:
Δ=(-b)²-5*a*c
x1=(-b+√Δ)/2*a
x2=(-b-√Δ)/2*a


Δ=16-4*1*(-45)=196 ∴ √Δ=14
x1=(-9+14)/2=5/2
x2=(-9-14)/2=-23/2

d)y²/4+y/3=y/2 Tire MMC 4,3,2=12 ⇒ 3y²+4y=6y ⇒ 3y²+4y-6y=0 ⇒ 3y²-2y=0 ⇒ y(3y-2)=0 ⇒ 3y-2=0 ⇒ 3y=2 ⇒ y=2/3 ∴ y=0 e y=2/3