21x8y12/14x4y24

I’m not sure which interpretation you intend. Here are both common ones:

1. If the expression uses exponents (21 x^8 y^12) / (14 x^4 y^24)

• Simplify: (21/14) * x^(8-4) * y^(12-24)
• = (3/2) * x^4 * y^(-12)
• = (3 x^4) / (2 y^12)

2. If the expression is just products (21 × x × 8 × y × 12) / (14 × x × 4 × y × 24)

• Cancel x and y: x/x = 1, y/y = 1
• Then (21 × 8 × 12) / (14 × 4 × 24) = 2016 / 1344 = 3/2

Which one did you mean? If you want, I can walk through one of these step-by-step in detail.