Can someone teach me how to solve this problem please:)

From second equation    x = 3 + y    sub into first equation

 

(y+3)^2 + y^2 = 34

y^2 + 6y+9 + y^2 - 34 =0

2y^2 + 6y - 25 = 0             now use quadratic formula to find the y values    

                                    use these values in the original equations to find the corresponding 'x' values