Question

Stiind ca ×:4mai mic cu 30 Calculeaza 2×

Answer 1

$\it \dfrac{x}{4} \ \textless \ 30 \Rightarrow x \ \textless \ 30\cdot4 \Rightarrow x\ \textless \ 120|_{\cdot2} \Rightarrow 2x\ \textless \ 240 \Rightarrow 2x\in(-\infty,\ 240)$