Răspuns:
Explicație pas cu pas:
a) delta= 1+24=25 x1,x2=(1+-5)/2
b) delta=1-4 < 0 nu are r ad. reale
c) delta=64-64 = 0 x1,x2= 4
d) delta = 49+32=81 x1,x2= (7+-9)/2
e) x<>-5 si x<>-2
(3x-7)(x+2)=(x-3)(x+5)
3x^2-x-14=x^2+2x-15
2x^2-3x+1= 0 delta=9-8=1 x1.x2=(3+-1)/2
i) x<>12 si x<>6
notam x-6=y
y/(y-6)-(y-6)/y=5/6
6(y^2-y^2+12y-36)=5y(y-6)
72(y-6)=5y(y-6)
(72-5y)(y-6)=0
y-6 = 0 x-6=6 x=12 nu convine
y=72/5 x-6 =72/5 x=102/5 convine
Cam atat !
