Question

Determinati numerele naturale x, stiind ca 5*x+4<16; 4*x-12<=15; 5la puterea 2*x+1<125; 7*x-3<=5*x+13; 2*x+4

Answer 1

[tex]a)5*x+4\ \textless \ 16\\ 5*x\ \textless \ 16-4\\ 5x\ \textless \ 12\\ x\ \textless \ \frac{12}{5} [/tex]
x∈( - infinit; 12/5)
$b) 4*x-12 \leq 15\\4x \leq 15+12\\4x \leq 27\\x \leq \frac{27}{4}$
x∈( - infinit; 27/4]
$c) 5^{2}*x+1\ \textless \ 125\\ 25x\ \textless \ 125-1\\25x\ \textless \ 124\\x\ \textless \ \frac{124}{25}$
x∈( - infinit; 124/25)
$7*x-3 \leq 5*x+13\\ 7x-5x \leq 13+3\\2x \leq 16\\x \leq 8$
x∈( - infinit; 8]