body{margin:0;} noscript{z-index: 10000; position: fixed; display: block; height: 100%; width: 100%; background: #fff;} noscript .fa{font-size: 40px; display:block; color: #daa520;} noscript div{margin-top: 6%; padding-left: 20px; padding-right: 20px; text-align: center;} ! You must have JavaScript enabled to use this site.

← Using Ratios and Solving Proportions

Rule

Cross Products Property

In a proportion, the product of the extremes is equal to the product of the means.

a/b=c/d ⇒ ad=bc

This property is also known as cross-multiplication or Means-Extremes Property of Proportion.

Proof

Cross Products Property

The Cross Products Property can be proven by using the Properties of Equality.

a/b=c/d

LHS * b=RHS* b

a=c/d* b

MoveRightFacToNum

a/c* b = a* b/c

a=cb/d

LHS * d=RHS* d

ad=cb

CommutativePropMult

Commutative Property of Multiplication

ad=bc

Exercises

Recommended exercises

To get personalized recommended exercises, please login first.

Return to lesson.