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a.\(x+\dfrac{4}{7}=\dfrac{38}{21}\)
\(x=\dfrac{38}{21}-\dfrac{4}{7}\)
\(x=\dfrac{38}{21}-\dfrac{12}{21}=\dfrac{26}{21}\)
b.\(x-\dfrac{1}{3}=\dfrac{7}{45}:\dfrac{2}{15}\)
\(x-\dfrac{1}{3}=\dfrac{7}{6}\)
\(x=\dfrac{7}{6}+\dfrac{1}{3}\)
\(x=\dfrac{7}{6}+\dfrac{2}{6}=\dfrac{9}{6}\)
a)
(1/3-1/5)x1/4 = 1/3x1/4-1/5x1/4=1/12-1/20=1/30
(1/3-1/5)x1/4 = 2/15x1/4=1/30
b)
2/5 x 3/7 + 2/5 x 4/7= 6/35 + 8/35 = 14/35 = 2/5
2/5 x 3/7 + 2/5 x 4/7= (3/7+4/7) x 2/5 = 1 x 2/5 = 2/5
a: C1: (1/3-1/5)*1/4
=2/15*1/4=2/60=1/30
C2: (1/3-1/5)*1/4
=1/3*1/4-1/5*1/4
=1/12-1/20=1/30
b: C1: 2/5*3/7+2/5*4/7
=6/35+8/35=14/35=2/5
C2: 2/5*3/7+2/5*4/7
=2/5(3/7+4/7)
=2/5*1=2/5
a) \(\dfrac{9}{7}\div x=\dfrac{3}{5}\)
\(x=\dfrac{9}{7}\div\dfrac{3}{5}\)
\(x=\dfrac{15}{7}\)
b) \(x+\dfrac{1}{3}=\dfrac{8}{6}-\dfrac{1}{2}\)
\(x+\dfrac{1}{3}=\dfrac{5}{6}\)
\(x=\dfrac{5}{6}-\dfrac{1}{3}\)
\(x=\dfrac{1}{2}\)
Nửa chu vi thửa ruộng là
100:2=50(m)
Chiều dài thửa ruộng là '
50:(4+1)x4=40(m)
Chiều rộng thửa ruộng là
50:(4+1)x1=10(m)
Diện tích thửa ruộng là
40x10=400(m2)
Thu được :
400:2x3=600(kg)
Đáp số....
\(a.x+\dfrac{3}{7}=\dfrac{2}{5}:\dfrac{18}{35}\\x+\dfrac{3}{7}=\dfrac{2}{5}\times\dfrac{35}{18} \\ x+\dfrac{3}{7}=\dfrac{7}{9}\\ x=\dfrac{7}{9}-\dfrac{3}{7}\\ x=\dfrac{22}{63}\)
\(b.x\times\dfrac{5}{9}=\dfrac{4}{5}-\dfrac{1}{3}\\x\times\dfrac{5}{9}=\dfrac{7}{15}\\ x=\dfrac{7}{15}:\dfrac{5}{9}\\ x= \dfrac{21}{25}\)
a. x + \(\dfrac{3}{7}\)= \(\dfrac{2}{5}:\dfrac{18}{25}=>x+\dfrac{3}{7}=\dfrac{2}{5}\)x\(\dfrac{35}{18}=>x+\dfrac{3}{7}=\dfrac{7}{9}\)
=> x = \(\dfrac{7}{9}-\dfrac{3}{7}=\dfrac{49}{63}-\dfrac{27}{63}=\dfrac{22}{63}\)
b. \(x\) x \(\dfrac{5}{9}\)= \(\dfrac{4}{5}-\dfrac{1}{3}\)
=> \(x\) x \(\dfrac{5}{9}\)= \(\dfrac{12}{15}-\dfrac{5}{15}=>x\) x \(\dfrac{5}{9}\)= \(\dfrac{7}{15}\)
=> x = \(\dfrac{7}{15}:\dfrac{5}{9}\)
=> x = \(\dfrac{21}{25}\)
a) 2 + 1/3 - x = 1 + 1/4
7/3 -x = 5/4
x = 7/3 - 5/4
x = 13/12
b) (2/7 x 2) : x = 1 :7/2
4/7 : x = 2/7
x = 4/7 : 2/7
x = 2
a) 2 + 1/3 - x = 1 + 1/4
7/3 -x = 5/4
x = 7/3 - 5/4
x = 13/12
b) (2/7 x 2) : x = 1 :7/2
4/7 : x = 2/7
x = 4/7 : 2/7
x = 2