Question

Solve:$7-7x\ge 37$ when $x$ is an natural number.

Answer 1

$7-7x\ge 37$

$\Rightarrow 7-7x-7\ge 37-7$

$\Rightarrow -7x\ge 30$

$\Rightarrow 7x\le -30$

$\Rightarrow x\le \frac{-30}{7}$

$\therefore x\in \varphi$