There are 55 people in class 61, class 62.57 to make the ratio of class 61 to class 62 7:9, how many people should be lost in class 61 to class 62

There are 55 people in class 61, class 62.57 to make the ratio of class 61 to class 62 7:9, how many people should be lost in class 61 to class 62

If class 61 is assigned to class 62, then class 61 is (55-x) and class 62 is (57 + x)
(55-x):(57+x)=7:9
That is, (55-x) = 7 (57 + x)
495-9x=399+7x
7x+9x=495-399
16x=96
x=6
A: six people should be transferred from class 61 to class 62