Help I'm doing an assignment and im stuck

X+ y = 5 ; x - y =3 solve using linear combination

Solve each equation using the quadratic formula. find the exact solutions. 6n^2 + 4n - 11

Aaron invested a total of $4,100, some in an account earning 8% simple interest, and the rest in an account earning 5% simple interest. how much did he invest in each account if after one year he earned $211 in interest? select one: a. $200 at 8%, $3,900 at 5% b. $3,200 at 8%, $900 at 5% c. $900 at 8%, $3,200 at 5% d. $3,900 at 8%, $200 at 5%