Solve the proportion x/42=3/7 using two different methods explain each strategy

Strategy 1: Horizontal method (less common)
Do  and 
go across and see how 42 and 7 relate to each other
42/7 is 6
This means that the numerator of 3  would need to be multiplied by 6 to get X 
Due to the fact that both fractions have to be equivalent to each other
3 x 6 would be 18
answer is x= 18
You can check by doing 18/42 = 3/7 and checking across
18 divided by 6 is 3
42 divided by 6 is 7
This makes them equivalent 
strategy 2: Cross multiplication (easier and more common)
In this method, all you do is multiply the two opposite numbers of the fractions and then divide the product by the number across from the x.
3 x 42= 126
126/ 7 = 18
Thus, you get the same answer.