= , (1) = . (2) ================> 5*(K-38) = 2S, (3) 13K = 8*(S-38). (4) ================> 5K - 2S = 5*38, (5) 13K - 8S = -8*38. (6) Multiply eq(5) by 4 (both sides). The modified system is 20K - 8S = 20*38, (7) 13K - 8S = -8*38. (8) Now subtract eq(7) from eq(8) (both sides). You will get 20K - 13K = 20*38 - (-8)*38, or 7K = 20*38 + 8*38 = 28*38 ====> K = = 4*38 = 152. Then from (5), 2S = 5K - 2*38 = 5*152 - 2*38 = 684 ====> S = = 342. Answer. K = 152, S = 342.