How is cross multiplication used in solving proportions

Answer 1

Cross multiplication is used in solving proportions to find the value of an unknown variable.

When you have a proportion such as

a/b = c/d

you can use cross multiplication to solve for the unknown variable.

To do this, you would multiply the numerator of the first fraction by the denominator of the second fraction and set it equal to the product of the denominator of the first fraction and the numerator of the second fraction, like this:

(a x d) = (b x c)

Then, you would simplify the equation and solve for the unknown variable.

For example, if you have the proportion 3/4 = x/8, you would cross multiply to get:

3 x 8 = 4 x x

24 = 4x

x = 6

So, in this case, the unknown variable x is equal to 6.