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\(A=\frac{5}{9}.\frac{7}{13}+\frac{5}{9}.\frac{6}{13}\)(( . là dấu nhân nha )
\(A=\frac{5}{9}.\left(\frac{7}{13}+\frac{6}{13}\right)\)
\(A=\frac{5}{9}\)
\(B=\left(\frac{1}{19}+\frac{12}{999}+\frac{123}{9999}\right).\left(\frac{1}{2}-\frac{1}{3}-\frac{1}{6}\right)\)
Mà \(\frac{1}{2}-\frac{1}{3}-\frac{1}{6}=0\)
\(\Rightarrow B=0\)
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2/5 + 7/12 + 13/12
= 2/5 + 20/12
= 2/5 + 5/3
= 6/15 + 25/15
= 31/15
k nha:))
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13\(\times\)2-5\(\times\)2
=26-10
=16
tick nha các bạn mình tính kỹ rồi
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X = ( 1+10 ) * 10 / 2 = 11 * 10 / 2 = 110 / 2 = 55
X= (2+20) * 10 /2 = 110
X= (1+19)*10/2= 100
1+2+3+4+5+6+7+8+9+10= (10+1)X10 : 2 = 55
2+4+6+8+10+12+14+16+18+20 = (20+2)x10 : 2 = 110
1+3+5+7+9+11+13+15+17+19 = (19+1) x 10 : 2 = 100
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TÌM SỐ DƯ TRONG PHÉP TÍNH SAU
34:5 dư 4 23:3 dư 2 33:4 dư 1
21:2 dư 1 13:2 dư 1 17:2 dư 1
k nha
๖ۣۜH๖ۣۜU๖ۣۜY ๖ۣۜR๖ۣۜI๖ۣۜO
34:5 dư 4 23:3 dư 2 33:4 dư 1
21:2 dư 1 13:2 dư 1 17:2 dư 1
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1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+................+200
Ss hạng là: ( 200 - 1 ) : 1 + 1 = 200
Tổng là : ( 1 + 200 ) . 200 : 2 = 20100
5/2 : 13/2 = 5/2 * 2/13 = 5/13