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222-9+11+12:2*14+14 = ? ( )

Toán Lớp 9: Rút gọn a,√11 + 4√7 – √11- 4√7 b, √19 – 8√3 + √19 + 8√3 c, √9 + 4√2 + √9 – 4√2 d,√28 – 6√3 – √28 + 6√3 e, √21 – 12√3 – √21 + 12√3 f, √2

Tháng Mười Một 13, 2022 Toán học 2 Comments 0 views

Toán Lớp 9: Rút gọn
a,√11 + 4√7 – √11- 4√7
b, √19 – 8√3 + √19 + 8√3
c, √9 + 4√2 + √9 – 4√2
d,√28 – 6√3 – √28 + 6√3
e, √21 – 12√3 – √21 + 12√3
f, √29 + 12√5 – √29 – 12√5
g, √5 + 2√6 – √5 + 2√6
h, √8 – 2√15 + √8 + 2√15

Comments ( 2 )

  1. kimlien
    kimlien
    13 Tháng Mười Một, 2022 at 6:40 chiều
    Reply
    a)
    \sqrt{11} + 4 \sqrt{7} – \sqrt{11} – 4 \sqrt{7}
    = (\sqrt{11} – \sqrt{11}) + (4\sqrt{7} – 4\sqrt{7})
    = 0 + 0
    = 0
    b)
    \sqrt{19} – 8 \sqrt{3} + \sqrt{19} + 8\sqrt{3}
    = (\sqrt{19} + \sqrt{19}) + ( 8\sqrt{3}  – 8\sqrt{3})
    =  2 \sqrt{19}
    c)
    \sqrt{9} + 4 \sqrt{2} + \sqrt{9} – 4 \sqrt{2}
    = ( \sqrt{9} + \sqrt{9}) + (4 \sqrt{2} – 4 \sqrt{2})
    = 2 . \sqrt{9}
    = 2 . 3  = 6
    d)
    \sqrt{28} – 6 \sqrt{3} – \sqrt{28} + 6 \sqrt{3}
    = (\sqrt{28}  -\sqrt{28}) + (6 \sqrt{3} – 6\sqrt{3})
    = 0 + 0
    = 0
    e)
    \sqrt{21} – 12 \sqrt{3} – \sqrt{21} + 12 \sqrt{3}
    = (\sqrt{21} – \sqrt{21}) + (12 \sqrt{3}  – 12 \sqrt{3})
    = 0 + 0
    = 0
    f)
    \sqrt{29} + 12 \sqrt{5} – \sqrt{29} – 12 \sqrt{5}
    =  (\sqrt{29} – \sqrt{29}) + (12\sqrt{5} – 12\sqrt{5})
    = 0 + 0
    = 0
    g)
    \sqrt{5} + 2 \sqrt{6} – \sqrt{5} + 2 \sqrt{6}
    = (\sqrt{5} – \sqrt{5}) + (2\sqrt{6} + 2 \sqrt{6})
    = 4 \sqrt{6}
    h)
    \sqrt{8} – 2 \sqrt{15} + \sqrt{8} + 2 \sqrt{15}
    = (\sqrt{8} + \sqrt{8}) + (2\sqrt{15} – 2 \sqrt{15})
    =  2 \sqrt{8}
    = 2 . \sqrt{4} . \sqrt{2}
    = 2 . 2 . \sqrt{2} = 4\sqrt{2}
     

  2. diemchau
    diemchau
    13 Tháng Mười Một, 2022 at 6:40 chiều
    Reply
    a) \sqrt{11}+4\sqrt{7}-\sqrt{11}
    =(\sqrt{11}-\sqrt{11})+(4\sqrt{7}-4\sqrt{7})
    =0
    b) \sqrt{19}-8\sqrt{3}+\sqrt{19}+8\sqrt{3}
    =(\sqrt{19}+\sqrt{19})-(8\sqrt{3}-8\sqrt{3})
    =2\sqrt{19}
    c) \sqrt{9}+4\sqrt{2}+\sqrt{9}-4\sqrt{2}
    =(\sqrt{9}+\sqrt{9}-(4\sqrt{3}-4\sqrt{3})
    =2\sqrt{9}
    =6
    d) \sqrt{28}-6\sqrt{3}-\sqrt{28}+6\sqrt{3}
    =(\sqrt{28}-\sqrt{28})-(6\sqrt{3}-6\sqrt{3})
    =0
    e) \sqrt{21}-12\sqrt{3}-\sqrt{21}+12\sqrt{3}
    =(\sqrt{21}-\sqrt{21})-(12\sqrt{3}-12\sqrt{3})
    =0
    f) \sqrt{29}+12\sqrt{5}-\sqrt{29}-12\sqrt{5}
    =(\sqrt{29}+\sqrt{29})-(12\sqrt{5}-8\sqrt{5})
    =0
    g) \sqrt{5}+2\sqrt{6}-\sqrt{5}+2\sqrt{6}
    =(\sqrt{5}+\sqrt{5})+(2\sqrt{6}+2\sqrt{6})
    =4\sqrt{6}
    h) \sqrt{8}-2\sqrt{15}+\sqrt{8}+2\sqrt{15}
    =(\sqrt{8}+\sqrt{8})-(2\sqrt{15}-2\sqrt{15})
    =2\sqrt{8}
    =4\sqrt{2}

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222-9+11+12:2*14+14 = ? ( )

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