Answer:
6
Step-by-step explanation:
Before solve this you've to know that,
( + ) × ( - ) = ( - )
( + ) × ( + ) = ( + )
( - ) × ( - ) = ( + )
Let us solve now.
13 + (-7)
13 - 7
= 6
Hope this helps you :-)
Let me know if you have any other questions :-)
