How do i solve a system of equation? can someone explain it to me? for example: x - y = 4 2x + y = 5

Find the nonpermissible replacement for binthis expression.b2/5b +5

At noon a tank contained 10cm water. after several hours it contained 7cm of water. what is the percent decrease of water in the tank?

Which situation could best be represented by this linear equation? 24x + 38y = 520 > if x represents the number of bracelets and y represents the number of rings, there were 24 more bracelets sold than rings. the total sales were $520. if x represents the number of bracelets and y represents the number of rings, there were 38 more bracelets sold than rings. the total sales were $520. if x represents the number of bracelets sold at $24 each and y represents the number of rings sold at $38 each, the total sales were $520 if x represents the number of bracelets and y represents the number of rings, there were 520 bracelets and rings sold. bracelets were $24, and rings were $38. e