What is the y intercept of the line given by the equation y=5 - 21

Where is the vascular system located

What are the answers for the following questions?

Religious conflict in northern ireland started with a) cultural differences resulting from viking invasions around 800 b) england’s split from the catholic church in the 1500s c) rebellions in ireland between 1916 and 1921 d) the norman invasion of england in 1066