Here, First two number represents Product of first two numbers in L.H.S.
For example, 5 * 3 = 15
Or 9 * 2 = 18
Now, second two numbers represent product of 1st & 3rd number,
For example, 5 * 2 = 10
Or 9 * 4 = 36
Now, Last two numbers represent Sum of 4 digit-number minus middle number.
So, 7 + 2 + 5 = 143547
In short, Your Final Answer would be: 143547
Hope this helps!