Tính nhanh
( 9x8-12-5x12) x ( 1+2+3+4+5)
Câu 11 : TÍNH NHANH
4x126x25
(9x8-12-5x12) x (1+2+3+4+5)
\(4\times126\times25\\ =\left(4\times25\right)\times126\\ =100\times126\\ =12600\)
\(\left(9\times8-12-5\times12\right)\times\left(1+2+3+4+5\right)\\ =\left(72-12-60\right)\times15\\ =\left(60-60\right)\times15\\ =0\times15\\ =0\)
\(4\times126\times25=\left(4\times25\right)\times126=100\times126=12600\\ \left(9\times8-12-5\times12\right)\times\left(1+2+3+4+5\right)\\ =\left(3\times3\times2\times4-12-5\times12\right)\times\left(1+2+3+4+5\right)\\ =\left(12\times6-12-5\times12\right)\times\left(1+2+3+4+5\right)\\ =\left[12\times\left(6-1-5\right)\right]\times\left(1+2+3+4+5\right)\\ =\left(12\times0\right)\times\left(1+2+3+4+5\right)\\ =0\times\left(1+2+3+4+5\right)=0\)
[9x8-12-5x12]x[1+2+3+4+5]
tính nhanh
Ta có: ( 9x8-12-5x12) x (1+2+3+4+5)
=( 72-12-60) x ( 1+2+3+4+5)
=(60-60) x (1+2+3+4+5)
=0 x (1+2+3+4+5)
=0
Mọi người tk cho mình nha. Mình cảm ơn trước vậy ^.<
(9 x 8 - 12 - 5 x 12) x (1 + 2 + 3 + 4 + 5)
= (72 - 12 - 60) x (1 + 2 + 3 + 4 + 5)
= ( 60 - 60) x (1 + 2 + 3 + 4 + 5)
= 0 x (1 + 2 + 3 + 4 + 5)
= 0
(9x8-12-5x12)x(1+2+3+4+5)
=(72-12-60)x(15)
=0x15
=0
Tính nhanh:
a,4x126x25
b,[9x8-12-5x12]x[1+2+3+4+5]
c, 3x9+18x2+2x9+9
d,2006x[43x10-2x43x5]+100
\(a)\) \(4.126.25=\left(4.25\right).126=100.126=12600\)
Tính
a) 8/21+13/21
b) 5/6:-7/12
c) -4 và 1/4 - 3/4
d) 7/9x8/17+7/9x15/17-7/9x6/17
a) \(\frac{8}{21}+\frac{13}{21}=\frac{8+13}{21}=\frac{21}{21}=1\)
b) \(\frac{5}{6}:\frac{-7}{12}=\frac{5}{6}.\frac{12}{-7}=\frac{10}{-7}\)
c) \(-4\frac{1}{4}-\frac{3}{4}=\frac{-17}{4}-\frac{3}{4}=\frac{-17-3}{4}=\frac{-20}{4}=-5\)
d) \(\frac{7}{9}.\frac{8}{17}+\frac{7}{9}.\frac{15}{17}-\frac{7}{9}.\frac{6}{17}\)
\(=\frac{7}{9}.\left(\frac{8}{17}+\frac{15}{17}-\frac{6}{17}\right)\)
\(=\frac{7}{9}.\frac{17}{17}\)
\(=\frac{7}{9}.1\)
\(=\frac{7}{9}\)
a) \(\frac{8}{21}+\frac{13}{21}=1\)
b) \(\frac{5}{6}\div\frac{-7}{12}=\frac{5}{6}.\frac{-12}{7}=\frac{-10}{7}\)
c) \(-4\frac{1}{4}-\frac{3}{4}=\frac{-17}{4}-\frac{3}{4}=-5\)
d) \(\frac{7}{9}.\frac{8}{17}+\frac{7}{9}.\frac{15}{7}-\frac{7}{9}.\frac{6}{17}=\frac{7}{9}.\left(\frac{8}{17}+\frac{15}{17}-\frac{6}{17}\right)=\frac{7}{9}.1=\frac{7}{9}\)
Tính nhanh ( 9 x 8 – 12 – 5 x 12 ) x ( 1 + 2 + 3 + 4 + 5)
( 9 x 8 – 12 – 5 x 12 ) x ( 1 + 2 + 3 + 4 + 5 )
= ( 72 – 12 – 60 ) x ( 1 + 2 + 3 + 4 + 5)
= 0 x ( 1 + 2 + 3 + 4 + 5 )
= 0
Tính nhanh:
( 9 x 8 – 12 – 5 x 12 ) x ( 1 + 2 + 3 + 4 + 5 )
Đáp án:
( 9 x 8 – 12 – 5 x 12 ) x ( 1 + 2 + 3 + 4 + 5 )
= ( 72 – 12 – 60 ) x ( 1 + 2 + 3 + 4 + 5)
= 0 x ( 1 + 2 + 3 + 4 + 5 )
= 0
(2 điểm) Tính nhanh
a. 4 x 126 x 25
b. (9 x 8 – 12 – 5 x 12) x ( 1 + 2 + 3 + 4 + 5)
a. 4 x 126 x 25
= (4 x 25) x 126
= 100 x 126
= 12600
b. (9 x 8 – 12 – 5 x 12) x ( 1 + 2 + 3 + 4 + 5)
= (72 – 12 – 60) x ( 1 + 2 + 3 + 4 + 5)
= 0 x ( 1 + 2 + 3 + 4 + 5)
= 0
Tính nhanh:
a) 4 x 126 x 25
b) ( 9 x 8 – 12 – 5 x 12 ) x ( 1 + 2 + 3 + 4 + 5)
tính nhanh
1. 2/3 + 4/9 + 1/5 + 2/15 +3/2 - 17/18
2. 13/28 x 5/12 - 5/28 x 1/12
3. 19/4 x 15/23 - 15/4 x 7/23 + 15/4 x 11/23
\(1,\frac{2}{3}+\frac{4}{9}+\frac{1}{5}+\frac{2}{15}+\frac{3}{2}-\frac{17}{18}\)
\(< =>\frac{4}{9}+\frac{3}{2}+\left(\frac{2}{3}+\frac{1}{5}+\frac{2}{15}\right)-\frac{17}{18}\)
\(< =>\frac{8}{18}+\frac{27}{18}+\left(\frac{10}{15}+\frac{3}{15}+\frac{2}{15}\right)-\frac{17}{18}\)
\(< =>\frac{35}{18}+1-\frac{17}{18}\)
\(< =>\frac{53}{18}-\frac{17}{18}\)
\(< =>2\)
\(2,\frac{13}{28}\cdot\frac{5}{12}-\frac{5}{28}\cdot\frac{1}{12}\)
\(< =>\left(\frac{13}{28}-\frac{5}{28}\right)\cdot\left(\frac{5}{12}-\frac{1}{12}\right)\)
\(< =>\frac{2}{7}\cdot\frac{1}{3}\)
\(< =>\frac{2}{21}\)
\(3,\frac{19}{4}\cdot\frac{15}{23}-\frac{15}{4}\cdot\frac{7}{23}+\frac{15}{4}\cdot\frac{11}{23}\)
\(< =>\frac{285}{92}-\frac{105}{92}+\frac{165}{92}\)
\(< =>\frac{15}{4}\)
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