26+15-24x4^4
Tính nhanh:
2x31x8+16x42+40+24x4
Tính nhanh:
a)24x4+24x3+24x2
b)2007x16-2007x14-2007x2+2007
\(a,24\times4+24\times3+24\times2\)
\(=24\times\left(4+3+2\right)\)
\(=24\times9\)
\(=216\)
\(b,2007\times16-2007\times14-2007\times2+2007\)
\(=2007\times\left(16-14-2+1\right)\)
\(=2017\times1\)
\(=2017\)
a, 24 x ( 4 + 3 + 2 ) = 24 x 9 = 216
b, 2007 x 16 - 14 - 2 + 1 ) = 2007 x 1 = 2007
a) 24x4+24x3+24x2 b)2007x16-2007x14-2007x2+2007
= 24x(4+3+2) =2007x(16-14-2+1)
=24x9 =2007x1
=216 =2007
Tính nhanh
(123+321)x(24x4-48x2)=
ghi rõ mới được k
\(CM:\sqrt[3]{26+15\sqrt{3}}+\sqrt[3]{26-15\sqrt{3}}=4\)
\(\sqrt[3]{26+15\sqrt{3}}+\sqrt[3]{26-15\sqrt{3}}=\sqrt[3]{8+12\sqrt{3}+18+3\sqrt{3}}+\sqrt[3]{8-12\sqrt{3}+18-3\sqrt{3}}=\sqrt[3]{\left(2+\sqrt{3}\right)^3}+\sqrt[3]{\left(2-\sqrt{3}\right)^3}=2+\sqrt{3}+2-\sqrt{3}=4\)
\(=\sqrt[3]{2^3+3.2^2.\sqrt{3}+3.2.\left(\sqrt{3}\right)^2+\left(\sqrt{3}\right)^3}+\sqrt[3]{2^3-3.2^2.\sqrt{3}+3.2.\left(\sqrt{3}\right)^2+\left(-\sqrt{3}\right)^3}\)
\(=\sqrt[3]{\left(2+\sqrt{3}\right)^3}+\sqrt[3]{\left(2-\sqrt{3}\right)^3}=2+\sqrt{3}+2-\sqrt{3}=4\)
5/2x3/7-3/4:7/3=
5/4:15/12-5/4:1/2=
1/26+7/30+12/26+8/3
\(\dfrac{5}{2}\times\dfrac{3}{7}-\dfrac{3}{4}\div\dfrac{7}{3}=\dfrac{5}{2}\times\dfrac{3}{7}-\dfrac{3}{4}\times\dfrac{3}{7}=\dfrac{5}{2}\times\dfrac{3}{7}-\dfrac{3}{7}\times\dfrac{3}{4}\)
\(=\dfrac{3}{7}\times\left(\dfrac{5}{2}-\dfrac{3}{4}\right)=\dfrac{3}{7}\times\dfrac{7}{4}=\dfrac{3}{4}\)
\(\dfrac{5}{4}\div\dfrac{15}{12}-\dfrac{5}{4}\div\dfrac{1}{2}=\dfrac{5}{4}\times\dfrac{12}{15}-\dfrac{5}{4}\times2\)
\(=\dfrac{5}{4}\times\left(\dfrac{12}{15}-2\right)\)
\(=\dfrac{5}{4}\times\dfrac{-6}{5}=\dfrac{-3}{2}\)
\(\dfrac{1}{26}+\dfrac{7}{30}+\dfrac{12}{26}+\dfrac{8}{3}=\left(\dfrac{1}{26}+\dfrac{12}{26}\right)+\left(\dfrac{7}{30}+\dfrac{8}{3}\right)\)
\(=\dfrac{1}{2}+\dfrac{29}{10}=\dfrac{17}{5}\)
Tính hợp lý: a) (-37)-14 - 26+37; b) (-15) - 23+ (-85) -77; c) (- 24) + 4 + (- 6) + 26; d) 34 + 35 + 36 + 37-14 - 15 - 16 - 17
A ,26/15+-7/13+-6/13-11/15 B, -3/4+4/13+-3/4×9/13+3/4 Hộ tui
A = (26/15 - 11/15) + (-7/13 + -6/13)
= 15/15 + -13/13
= 1 + (-1)
=0
a/\(\dfrac{26}{15}+-\dfrac{7}{13}+-\dfrac{6}{13}-\dfrac{11}{15}\)
\(=\left(\dfrac{26}{15}-\dfrac{11}{15}\right)-\left(\dfrac{7}{13}+\dfrac{6}{13}\right)\)
\(=1-1\)
\(=0\)
b/Sửa đề:
\(-\dfrac{3}{4}\cdot\dfrac{4}{13}+-\dfrac{3}{4}\cdot\dfrac{9}{13}+\dfrac{3}{4}\)
\(=-\dfrac{3}{4}\cdot\left(\dfrac{4}{13}+\dfrac{9}{13}\right)+\dfrac{3}{4}\)
\(=-\dfrac{3}{4}\cdot1+\dfrac{3}{4}\)
\(=-\dfrac{3}{4}+\dfrac{3}{4}\)
\(=0\)
câu b ko tính nhanh được, nếu đề sai thì đã có bài của ctv rồi nhé
Cứuuuuuuuuuuuuuuuuu
26/5 + 15/4 =
26/5 + 15/4
= 26x4/5x4 + 15x5/4x5
= 104/20 + 75/20
= 179/20
Tính: a) (56 - 26).(-4) + 61.(-11 -19); b) (-23).(35 -15) - 35.(15 - 23).