# Math Help - Quick question about expressions

1. ## Quick question about expressions

The answer is A but idk how its A... Please explain. Thanks!!

2. ## Re: Quick question about expressions

Originally Posted by asilvester635
The answer is A but idk how its A... Please explain. Thanks!!
$20-\tfrac{4}{5}x\ge 16$ is equivalent to $100-4x\ge 80.$

3. ## Re: Quick question about expressions

Equivalently, $20- \frac{4}{5}\ge 16$ is equivalent to $20\ge \frac{4}{5}x+ 16$ (add $\frac{4}{5}x$ to both sides) which equivalent to $20- 16= 4\ge \frac{4}{5}x$ (subtract 16 from both sides).

Now multiply both sides by the positive number $\frac{5}{4}$:
$\frac{5}{4}(4)= 5\ge x$.

4. ## Re: Quick question about expressions

Thank you so much!!!