Question

Am nevoie de ex 1 rapid va rog

Answer 1

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 !