The correct answer to this open question is the following.
A specific situation where the principle of checks and balances could be used for the good of the people would be the following.
When the President of the United States sends a bill to the US Congress, thinking that would benefit the economy of the country. For instance, a new tax. When the bill gets to Congress, the House of Representatives decides that this bill is no good for the American people and that is biased to benefit just a political group or the President's Party. Then Congress did not pass the new bill proposed by the executive branch.
Or it could be the other way around. That the President receives a law from the legislative branch and the President considers it is biased to benefit a political group. Then the President exerts his power to veto the law.
The system of checks and balances has been one of the best things implemented by the framers of the Constitution. It guarantees that none of the three branches of the federal government has more power over the other two.
