Answer:
a=9
Step-by-step explanation:
To solve this proportion, we have to get the variable, a, by itself.
First, cross multiply.
6/a=18/27
Multiply the denominator of the first fraction by the numerator of the second, and the numerator of the second by the denominator of the first.
a*18=6*27
18a=162
Now, 18 and a are being multiplied. In order to get a by itself, perform the opposite of what is being done. They are being multiplied, so the opposite would be division. Divide both sides by 18.
18a/18=162/18
a=162/18
a=9
So, the proportion, with 9 substituted in for a, will be:
6/9=18/27