Question

(6-9+1)-[?] = 15
What number completes this equation?

Answer 1

Explanation:

(6-9+1)-x=15

6-9= -3

-3+1 = -2

-2+2-x=15+2

-x=17 (divide both sides by -1)

x=-17

Answer 2

so instead of the question mark u may substitute the value -17

(6-9+1)-(-17)=15