Proportions

Cross multiplying is a great way to help solve a proportion. For example, 2/5 = x/35. First, you multiply the numerator 2 by the denominator 35. 2 times 35 is 70. Next, you multiply the denominator 5 by the numerator x which is 5x. The new problem is 5x=70. 70 ÷ 5 is 14. X=14. This problem is proportional. Some problems can be wrong. For example, 2/3 = x/12; 2x = 36; x = 18. First, you multiply 2 by 12 and get 24. 3x=24. 24÷3=8. X=8! Cross multiplying really does help you solve proportions.