54x68 in distributive property

Which recursive formula can be used to determine the total amount of money earned in any year based on the amount earned in the previous year? f(n+1)=f(n)+5

Solve the given system of equations. 2y= -x+9 , 3x-6= -15

Me solve this problem, and someone clearly explain to me how to solve it.1.) use the value of the discriminant to determine if the given trinomials has 2 real solutions, 1 real solution, or no real solutions.a.  x2  − 4x  − 7 = 0b. 4r2  + 11r  − 3 = 0c. 3m2  + 7 = 0d.  t2  + 2t  + 1 = 0