Question

Urgent, va rog!

Determinati multimile de adevar pentru predicatele:

p(x):3(x-2) - 5x = 4, x apartine R

p(x): 5x - 7 (mai mic sau egal) 8, x apartine N

p(x): x² - x - 20 = 0, x apartine Z.

Answer 1

Explicație pas cu pas:

a) 3x-6-5x=4, -2x=4+6,

-2x=10, x = -2, Sp(x)=-2

b) 5x-7<=8, 5x<=8+7, 5x<=15,

x<=3, Sp(x)={0, 1,2,3}

c) x^2-16-x-4=o, (x-4)(x+4)-(x+4)=0

(x+4)(x-4-1)=0,

(x-4)(x-5)=0, x=4 , x=5, Sp(x)={4,5}