Question

Ajutatima varog va dau coroana​

Answer 1

Răspuns:

Explicație pas cu pas:

a)x²-9x+18=0

x1,2=9±√81-72/2=9±3/2     x1=9+3/2=12/2=6     x2=9-3/2=6/2=3

x1=9  ;x2=3

b)2x²-7x-4=0

x1,2=7±√49+32/4=7±9/4     x1=7+9/4=16/4=4     x2=-2/4=-1/2

x1=4     x2=-1/2

c)4x²-12x+9=0     (2x-3)²=0     x1,2=3/2

d)3x²+4x+5=0   x1,2=-2±√4-15/3     Δ<0   ecuatia Nu are solutii reale