Question

rezolvați ecuatiile a) x(x+7)=0 ;b) (x+1)(x-6)=0. Sa văd rezolvarea va rog!

Answer 1

a) x(x+7)=0
 x^2+7x=0

Δ=b^2 - 4·a·c
Δ=7^2-4·1·0
Δ=49

X1=-b-√Δ / 2a
X1=-7-7 / ·1 = -14/2 = -7

X2=-b+√Δ / 2a
X2=-7+7 / 2 = 0/2 = 0

b)(x+1)(x-6)=0
x^2-6x+x-6=0
x^2-5x-6=0

Δ=b^2 - 4·a·c
Δ=(-5)^2 - 4·1·(-6)
Δ=25+24
Δ=49

X1=-b-√Δ / 2a
X1=5-7/2 = -1

X2=-b+√Δ / 2a
X2=5+7/2 =6