Find the missing value

Question

(?)(7y5-3y)=35y14-15y10

Answer 1

We need to find the value that when multiplied by 7y5 - 3y gives us 35y14 - 15y10.

If we let (?) = 5y9, then:

5y9(7y5 - 3y) = 35y14 - 15y10
= 35y14 - 15y10 + (-21y14 + 9y10)
= 35y14 - 21y14 - 15y10 + 9y10
= 14y14 - 6y10

Therefore, the missing value is 5y9.