Question

Repede va rog frumos!!i

Answer 1

Răspuns:

7.

I : (x-4)(x-5)<0 =>x<{4,5}

II : (4-x)(-x-1)<0 =>x<{4} și x>{-1}

8.

rad[9-4rad5]=rad(9-80)=rad[(9+rad(81-80)/2] - rad[9-rad(81-80)/2]

=rad5 - 2

x(rad5 - 2)<_ 3rad5 - 6

x <_ (3rad5 - 6)/(rad5 - 2)

x <_ (3rad5 - 6)(rad5 + 2)/1

x <_ 15-12

x <_ 3 =>x € {1, 2, 3}

9.

x^2 + 2x + 1 - 3 <_ 0

x^2 + 2x - 2 <_ 0

delta=4-4•(-2)=4+8=12 =>rad.delta=2rad3

x1=(-2-2rad3)/2=(-1-rad3)

x2=(-2+2rad3)/2=rad3-1