Question

Triple a number, x, increased by 1 is between -20 and 10. What are the solutions for x?

Answer 1

Hello,
$-20 \leq 3x+1 \leq 10\\ \Rightarrow\ -21 \leq 3x \leq 9\\ \Rightarrow\ -7 \leq x \leq 3\\ Sol=[-7\ 3]\ if\ x\ is\ a\ real.$