Question

Please help I need help I will mark brainliest

Answer 1

a:

Just divide both sides by 7. Since 7 is positive, you don't need to change the inequality sign:

$7j>77\iff j>11\}$

In set notation, we write

$\{j \in \mathbb{R}\ :\ j>11$

b:

Subtract 9 from both sides:

$17\leq x+9 \iff 8\leq x$

In set notation, we write

$\{x \in \mathbb{R}\ :\ x\geq 8\}$