The ratio of two numbers is equivalent to a fraction, and the numerator and denominator are multiplied or divided by a non-zero number at the same time, and the fraction remains unchanged, which is also the basis of general fraction and reduced fraction.

The ratio of three numbers is a generalization of two numbers. Every number in the ratio of three numbers is multiplied or divided by a non-zero number, and the ratio remains unchanged. The problem is that all three numbers are multiplied by xyz, and the ratio remains the same. This will simplify the scale.

Hope to adopt, thank you.