Answer: " 4x + 2xy - 7pq " .
___________________________________
Explanation:
___________________________________
Given: " 4x - 7xy + 9xy - 7pq " ; Simplify the expression;
___________________________________
Combine the "like terms:
___________________________________
-7xy + 9xy = 2xy ;
___________________________________
Now, rerewrite the expression, substituting the "-7xy + 9xy"; with " + 2xy" ;
___________________________________
→ " 4x + 2xy - 7pq " .
___________________________________