Let, the number of students in history class be x.
Given there are 8 more students are in a math class than in a history class.
So, the number of students in math class = (x+8)
Given, ratio of the students in the math class to the history class = 9:7
So we can write
(x+8)/x = 9/7
To solve this for x, first we have to cross multiply.
7(x+8) = 9x
Now we have to expand the left side by dustributing 7.
7x+56 = 9x
To get x, we have to take x terms together. So we will move 7x to the right side by subtracting 7x from both sides.
7x-7x+56 = 9x-7x
0+56 = 2x
56 = 2x
2x= 56
We can get x by dividing 2 to both sides now.
2x/2 = 56/2
x = 28
So we have got the number of students in history class = 28
Therefore, the number of students in maths class = 28+8 = 36
So 36 is the required answer here.
