How do you solve #7/12 = x/9#?

1 Answer
May 1, 2016

An alternative approach, which of course gives the same answer, is to use the method of cross-multiplication.
This can only be done if there is ONE term (a fraction) on each side of an EQUAL sign.

This has the same effect as multiplying both side by the LCM of the denominators, but the result is obtained more quickly. This process also removes the fractions. Multiply the combination which has the variable first, so that the variable ends up on the left side, which simply feels more comfortable.

#12x = 7xx9#

#x = (7xx9)/12# #x = 21/4 #

The answer can be left in this form, which is preferable, or given as 5#1/4# or 5.25