Question

aflati mulțimea B va roggg​

Answer 1

Răspuns:

Explicație pas cu pas:

B=3x-7/2x+3∈Z

2x+3/ 2x+3→2x+3/6x+9

2x+3/2x-7 →2x+3/6x-21

le scadem

2x+3/30→2x+3∈D₃₀...............D₃₀=divizorii lui 30

2x+3∈{1,2,3,5,6,10,15,30 ,-1 ,-2 ,-3 ,-5 ,-6,-10 ,-15 ,-30}

2x∈{ -2 ,-1 ,0 , 2,3,7,12,27,-4,-5,-8,-9,-13 ,-18 ,-33}

x={ -1,0,1,6,-2,-4,-9 }

B={-1,0,1,6,-2,-4,-9 }

Answer 2

Răspuns:

R

Explicație pas cu pas:

x aparține Z

(3x-7)/(2x+3) aparține Z

1) (3x-7)=±(2x+3)

+. x1=10

-. 5x2=4 x2=4/5 nu apartine Z

2) 2x+3=±1

+ x3=-2/2=-1 x3=-1

- x4=-4/2=-2. x4=-2

3) 3x-7=0. x5=7/3 nu apartine Z

2(3x-7)=(2x+3)

6x-14=2x+3

4x=17 x=17/4nu apartine

B={-1;-2;10}