Question

Faceti ex E1 macar a b c d e

Answer 1

Răspuns:

Explicație pas cu pas:

Answer 2

Explicație pas cu pas:

a)3x²-x-10=0

Δ=1+4*3*10=121⇒√121=11

x1=(1+11)/3*2=12/6=2

x2=(1-11)/2*3=-5/3

b)-3x²-5x+12=0

3x²+5x-12=0

Δ=25+144=169⇒√169=13

x1=(-5+13)/6=8/6=4/3

x2=(-5-13)/6=-18/6=-3

c)

9x²-12x+4=0⇒(3x-2)²=0⇒x=2/3

d)

20x-4-25x²=0⇒25x²-20x+4=0⇒(5x-2)²=0⇒x=2/5

e)-10x²+4x-1=0

Δ=16-40=-24<0⇒x∉R

Bafta!