We can solve this question using matching operations (see video below)

Given:
Quantity A: \( 4x \)
Quantity B: \( \frac{x}{5}\)

Multiply both quantities by \(5\) to get:
Quantity A: \( 20x \)
Quantity B: \(x\)

Subtract \(x\) from both quantities:
Quantity A: \( 19x \)
Quantity B: \(0\)

At this point, you probably already see that quantity A is greater, but we can be even more certain of this by dividing both quantities by \(19\) to get:
Quantity A: \( x \)
Quantity B: \(0\)

Since it's given that \(x>0 \), the correct answer is A

RELATED VIDEO