Answer:
The executive branch can check the power of the legislative branch by vetoing a bill if the executive branch thinks that the bill will cause harm, or is simply not fair. Vetoing a bill means the president says “No” to a bill that the legislative branch wants to pass and make a law.
The Supreme Court can check both the executive and legislative branches by using its power of judicial review. Judicial review is the power of the Supreme Court to determine if the actions of the legislative and executive branches are consistent with the Constitution, and to declare them null and void if they are not. For example, in Marbury v. Madison (1803), the Supreme Court struck down an act of Congress as unconstitutional for the first time.