03 THI T K H TH NG CHI U SÁNG BƯÆC 01 Q ¦ ¬ ¦ ¦ , BƯÆC 02 T ¢ µ BƯÆC 03 T ¢ = D R ¢ C (D + R ) VD: 1010 / [2*(10 + 10)] = 2,5 BƯÆC 04 T ¹ . . 102