Friday, April 3, 2009

Proportions

How do we solve proportions by using cross product?


You Cross multiplying is a great way to help solve a proportion. For example, = 15/h = 5/6. First, you multiply the numerator 15 by the denominator 6. 15 times 6 is 90. Next, you multiply the denominator h by the numerator 5 which is 5h. The new problem is 5h=90. 90 ÷ 5 is 18. X=18. 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.

No comments: