A country’s national debt was \(140\) million dollars in 2010. The debt increased at \(50\) million dollars per year. If this trend continues, when will the country’s national debt increase to \(640\) million dollars?
Assume the country’s national debt will become \(640\) million dollars \(y\) years after 2010. We can solve this problem using the equation:
Check whether \(10\) is a solution for \(y\) of this equation.