there are a few ways. let's look at 1/2 or the ratio 1 to 2 ( sometime written as 1:2) and compare it to 2 to 4 which I will write as 2/4 So one way is to multiply the bottom number on the first by the top number on the second. 2x2=4 and do the same with the remaining two numbers, 1x4=4 so they are the same and that means the ratios are the same. They used to call this multiplying the means and the extremes. In general a/b is equivalent to c/d if bc=ad. The other way is to put them both in lowest terms and compare. So 2/4 is 1/2 by dividing the numerator and denominator by 2.
Chat with our AI personalities
The ratios are equal if and only if their cross products are equal.
That is a/b = c/d iff ad = bc
If the cross-product are equal the ratios are equal. Thus, a/b = c/d if (and only if) ad = bc
Compare the simplified ratios, which are 1 : 3.
Two ratios that are equivalent are said to be in proportion
when a number of ratios give the same answer after solving the ratios the ratios are said to be equivalent ratios
Equivalent ratios are ratios that represent different numbers but the relationship between the numbers is same.