... n3/4)/(m1 /2 – n1 /2 ) –(m.n)1 /2 0 .25 =(m3 /2 – n3 /2 )/(m1 /2 – n1 /2 ) –(m1 /2 .n1 /2 ) 0 .25 = (m1 /2 – n1 /2 )(m + m1 /2 .n1 /2 + n)/(m1 /2 – n1 /2 ) – (m1 /2 .n1 /2 ) 0 .25 = m + n 0 .25 Σ 13 ... ]−∉=−∈=−∈−=⇔ 2; 249 2; 21 2; 21xxx+ y ( - 2 ) = 14, y ( - 1 ) = - 7, y ( 1 ) = 5, y ( 2 ) = 2 + [ ]14 )2( max 2; 2=−=−yy, [ ]7)1(min 2; 2−=−=−yy0,50 ,25 0 ,25 4b 3 điểm4b.1 1 điểm+ V=πR 2 h+ ... 25 6/1 025 VS.ADE = (25 6/1 025 ).VS.ABC = (25 6/1 025 ).1/3.SA.1 /2. AB.BC = (25 6/1 025 ).1/3.4.1 /2. 3.4 0 .25 = (25 6/1 025 ) .8 (cm3) 0 .25 4a 3 điểm4a.1 1 điểm+ Đk: x > - 5+ BPT 35>+⇔x0 ,25 0 ,25 495>⇔>+⇔xx...