Tinh bang cach thuan tien :
1+5+9+13+...+29
Tinh bang cach thuan tien:
5/9: 4/7+ 13/9 *7/4
\(\frac{5}{9}:\frac{4}{7}+\frac{13}{9}\cdot\frac{7}{4}\)
\(=\frac{5}{9}\cdot\frac{7}{4}+\frac{13}{9}\cdot\frac{7}{4}\)
\(=\left(\frac{5}{9}+\frac{13}{9}\right)\cdot\frac{7}{4}\)
\(=2\cdot\frac{7}{4}\)
\(=\frac{14}{4}\)
=\(\frac{5}{9}\)*\(\frac{7}{4}\)+\(\frac{13}{9}\)*\(\frac{7}{4}\)
=\(\frac{7}{4}\)*(\(\frac{5}{9}+\frac{13}{9}\))
=\(\frac{7}{4}\)*2
=\(\frac{7}{2}\)
tinh bang cach thuan tien nhat
2,9*5+2,9:0,25+5,8-29*0,1
\(2,9\times5+2,9:0,25+5,8-29\times0,1\)
\(=2,9\times5+2,9\times4-2,9+5,8\)
\(=2,9\times\left(5+4+1\right)+5,8\)
\(=2,9\times10+5,8\)
\(=29+5,8\)
\(=34,8\)
\(2,9\times5+2,9:0,25+5,8-29\times0,1\)
\(=2,9\times5+2,9\times4+2,9\times2-2,9\)
\(=2,9\times\left(5+4+2-1\right)\)
\(=2,9\times10\)
\(=2,9\)
tinh bang cach thuan tien 3/5 x 7/9 + 11/9 x 3/5 - 3/10. B 14/13 : 1/2 + 3/13 x2 -2 x 7/13
a) 3/5x7/9+11/9x3/5
=3/5 x(7/9+11/9)
= 3/5x2
=6/5
b)14/13:1/2+3/13x2-2x7/13
= 14/13 x 2 +3/13 x2 - 2x7/13
=2 x (14/13 +3/13 -7/13)
= 2 x 10/13
= 20/13
a) 3/5 x 7/9 + 11/9 x 3/5 - 3/10
= 3/5 x 7/9 + 11/9 x 3/5 - 3/5 x 2
= 3/5 x ( 7/9 + 11/9 - 2 )
= 3/5 x 0
= 0
b) 14/13 : 1/2 + 3/13 x 2 - 2 x 7/13
= 14/13 x 2/1 + 3/13 x 2 - 2 x 7/13
= ( 14/13 + 3/13 - 7/13 ) x 2
= 10/13 x 2 = 20/13
chẳng hiể gì cả
tinh bang cach thuan tien nhat:1+8+29+32
1 + 8 + 29 + 32
= ( 1 + 29 ) + ( 8 + 32)
= 30 + 40
= 70
mk nhóa
\(1+8+29+32\)
\(=\left(1+29\right)+\left(8+32\right)\)
\(=30+40\)
\(=70\)
Tinh bang cach thuan tien nhat 4/15+8/13+11/5+5/13
\(\frac{4}{15}+\frac{8}{13}+\frac{11}{15}+\frac{5}{13}\)
\(=\left(\frac{4}{15}+\frac{11}{15}\right)+\left(\frac{8}{13}+\frac{5}{13}\right)\)
\(=\frac{15}{15}+\frac{13}{13}\)
\(=1+1\)
\(=2\)
Chúc bạn học tốt nha !!!
\(\frac{4}{15}+\frac{8}{13}+\frac{11}{15}+\frac{5}{13}\)
\(=\left(\frac{4}{15}+\frac{11}{15}\right)+\left(\frac{8}{13}+\frac{5}{13}\right)\)
\(=1+1\)
\(=2\)
=(4/15+11/5)+(8/13+5/13)
=37/15+1=52/15
k mink nha
tinh bang cach thuan tien nhat
713*3+713*97
375*29-375-9
713*3+713*97
= 713 *(3+97)
= 713*100
= 71300
375*29-375-9
Sai đề rồi bạn thế này mới đúng
375*29-375*9
tinh bang cach thuan tien nhat11+21+19+29
\(\left(11+19\right)+\left(21+29\right)=30+50=80\)
tinh
M=9/40-11/60+13/84-15/112
(giai bang cach thuan tien)
Tinh bang cach thuan tien:
c)1/9+2/5+1/3+3/10
=(1/9+1/3)+(2/5+3/10) =(1/9+3/9)+(4/10+3/10) =4/9+7/10 =40/90+63/90 =103/90