Question

E(x) = -10x-5

VA ROG AM NEVOIE URGENT!!!​

Answer 1

Răspuns:

Explicație pas cu pas:

15-E(x)<=10

E(x)=-10x-5

15-( -10x-5)<=10

10X+20<=10

10x<=-10

x<=-1

care intersectata cu Z

x=-1;-2;-3;-4..samd

solutia este: nr.intregi negative

Answer 2

$\it De\ la \ subpunctul\ a),\ avem\ E(x)=-10x-5$

$\it |15-E(x)|\leq10 \Rightarrow |15+10x+5|\leq10 \Rightarrow |10x+20|\leq10 \Rightarrow \\ \\ \\ \Rightarrow 10|x+2|\leq10\bigg|_{:10} \Rightarrow |x+2|\leq1 \Rightarrow -1\leq x+2\leq1\bigg|_{-2} \Rightarrow \\ \\ \\ \Rightarrow -3\leq x\leq-1 \Rightarrow A=[-3,\ -1]\\ \\ A\cap\mathbb{Z}=\{-3,\ \ -2,\ \ -1\}$