3,63+5,13+6,63+8,13+9,63+11,13+12,63+14,13+15,63+17,13+18,63
=(3,63+5,13)+(6,63+8,13)+(9,63+11,13)+(12,63+14,13)+(15,63+17,13)+18,63
=8,76+14,76+20,76+26,76+32,76+18,63
=(8,76+14,76)+(20,76+26,76)+(32,76+18,63)
=23,52+47,52+51,39
=71,04+51,39
=122,43
CHÚC BN HOK TỐT