3x + 5y = 50 -----------------------------(1)
x + 5y = 31 -------------------------------(2)
subtract equation (2) from equation (1)
2x = 19
Divide both-side of the equation by 2
x = 19/2
x = 9.5
To get the value of y, substitute x = 9.5 in any of the equation and then solve for y
That is;
x + 5y = 31
9.5 + 5y = 31
subtract 9.5 from both-side of the equation
5y = 21.5
Divide both-side by 5
y = 4.3