Answer:
Step-by-step explanation:
you can bring -(7-3ab) to the other side of the equation . then you will have this : (a^2 - 5ab) + (2ab - a^2) = -7 + (7 - 3ab)
now look at this part : -7 + (7 - 3ab) (because adding is a associative procedure) you can get rid of -7 and 7 . then you will have only -3ab
so now this would look like this : (a^2 - 5ab) + (2ab - a^2) = -3ab
now take a look at the left of the equation : just like the last part we can simplify a^2 and - a^2 . and -5ab + 2ab would result in -3ab
because if you subtract -5ab from a^2 and subtract a^2 from 2ab ... then add then to each other would give you the same result
at the end you will have -3ab = -3ab which is a true conclusion.
