how is this written as an equation

Question

three and one-half times a number n is the opposite of seventh-ninths

Answer 1

It depends what you mean by "opposite".

 

Do you mean the reciprocal, which would be 9/7?

 

Or do you mean the negative of 7/9, which would be -7/9?

 

Whichever you mean mean, it would be basically the same:

 

3 1/2 n = (opposite)

 

It's better to avoid using mixed fractions in equations, so you could say 7/2 n = (opposite)