Question

Efectuati: 60x - x -2x -3x -....-10x < sau egal cu 49 - 2x.


Urgent!!!!

Answer 1

$x\in \mathbb_{N}$

$60x-x-2x-3x-...-10x\leq 49-2x \\ \\ 60x-x\cdot (1+2+3+...+10)\leq 49-2x \\ \\ 60x-x\cdot \dfrac{10\cdot (10+1)}{2}\leq 49-2x\\ \\ 60x-x\cdot \dfrac{10\cdot 11}{2}\leq 49-2x\\ \\ 60x-x\cdot 5\cdot 11\leq 49-2x \\ \\ 60x-55x\leq 49-2x \\ \\ 5x\leq 49-2x \\ \\ 5x+2x\leq49 \\ \\ 7x\leq 49 \\ \\ x\leq \dfrac{49}{7} \\ \\ x\leq 7\\ \\ S= \Big\{0,1,2,3,4,5,6,7\Big\}$