20 ≤ [tex] \dfrac{x}{7} [/tex]
Flip the left and right side
[tex] \dfrac{x}{7} [/tex] ≥ 20
Multiply both side by 7
[tex] \dfrac{x}{7} \times 7[/tex] ≥ 20 × 7
x ≥ 140
x is equal to 140 or bigger than 140.
First option is not the solution because it's smaller than 140
Second option is not the solution because it's smaller than 140
Third option is the solution because it's equal to 140
Fourth option is not the solution because it's smaller than 140
The only answer is third option
