\(a,50\%+\dfrac{7}{12}-\dfrac{1}{2}\\ =\dfrac{1}{2}+\dfrac{7}{12}-\dfrac{1}{2}\\ =\left(\dfrac{1}{2}-\dfrac{1}{2}\right)+\dfrac{7}{12}\\ =\dfrac{7}{12}\\ b,2022\times67+2022\times43-2022\times10\\ =2022\times\left(67+43-10\right)\\ =2022\times100\\ =202200.\\ c,125-25:3\times12\)

\(=25\times5-25:3\times12\\ =25\times\left(5-\dfrac{1}{3}\right)\times12\\ =25\times\dfrac{14}{3}\times12\\ =1400\)

a,50%+127​−21​=21​+127​−21​=(21​−21​)+127​=127​b,2022×67+2022×43−2022×10=2022×(67+43−10)=2022×100=202200.c,125−25:3×12

=25×5−25:3×12=25×(5−13)×12=25×143×12=1400=25×5−25:3×12=25×(5−31​)×12=25×314​×12=1400

a) 7/12

b) 202200

c) 1400

d) mình ko bt

b) 201400

c) 25

\(A=1+\dfrac{1}{5}+\dfrac{1}{25}+\dfrac{1}{125}+...+\dfrac{1}{625}+\dfrac{1}{78125}\)

\(=1+\dfrac{1}{5}+\dfrac{1}{5^2}+\dfrac{1}{5^3}+...+\dfrac{1}{5^7}\)

\(5A=5+1+\dfrac{1}{5}+\dfrac{1}{5^2}+...+\dfrac{1}{5^6}\)

\(\Leftrightarrow5A-A=5+1+\dfrac{1}{5}+\dfrac{1}{5^2}+...+\dfrac{1}{5^6}-1-\dfrac{1}{5}-\dfrac{1}{5^2}-\dfrac{1}{5^3}-...-\dfrac{1}{5^7}\)

\(\Leftrightarrow4A=5-\dfrac{1}{5^7}\Leftrightarrow A=\dfrac{5-\dfrac{1}{5^7}}{4}=\dfrac{\dfrac{390624}{78125}}{4}=\dfrac{390624}{312500}=\dfrac{97656}{78125}\)

\(50\%+\dfrac{7}{12}-\dfrac{1}{2}\)

\(=\dfrac{1}{2}+\dfrac{7}{12}-\dfrac{1}{2}\)

\(=\left(\dfrac{1}{2}-\dfrac{1}{2}\right)+\dfrac{7}{12}\)

\(=\dfrac{7}{12}\)

_______________

\(2022\cdot67+2022\cdot43-2022\cdot10\)

\(=2022\cdot\left(67+43-10\right)\)

\(=2022\cdot100\)

\(=202200\)

_____________________

\(10,3+6,9+8,7+13,1\)

\(=\left(13,1+6,9\right)+\left(10,3+8,7\right)\)

\(=20+19\)

\(=39\)

___________________

\(17,58\times43+57\times17,58\)

\(=17,58\times\left(43+57\right)\)

\(=17,58\times100\)

\(=1758\)

tớ ghi sai nên cập nhật lại câu hỏi, phần 3 các bạn trả lời sớm mà bị sai thì bỏ qua cho tớ nhé

\(50\%+\dfrac{7}{12}-\dfrac{1}{2}=\dfrac{1}{2}+\dfrac{7}{12}-\dfrac{1}{2}=\left(\dfrac{1}{2}-\dfrac{1}{2}\right)+\dfrac{7}{12}=\dfrac{7}{12}\)

\(2022\cdot67+2022\cdot43-2022\cdot10=2022\cdot\left(67+43-10\right)=2022\cdot100=202200\)

\(11,3+6,9+8,7+13,1=\left(11,3+8,7\right)+\left(6,9+13,1\right)=20+20=40\)

\(17,58\cdot43+57\cdot17,58=17,58\cdot\left(43+57\right)=17,58\cdot100=1758\)

a)  7 12

d) 0

b: \(=72\cdot4-3=288-3=285\)

a) 5 . 125 . 2 . 41 . 8

= (5 . 8) . (125 . 2) . 41

= 40 . 250 . 41

= 10 000 . 41

= 410 000

b) 25 . 7 . 10 . 4

= (25 . 4 ) . (10 . 7)

= 100 . 70

= 7000

Chúc bạn học tốt!! ^^

a,5.125.2.41.8=(125.8).(2.5).41=1000.10.41=410000

b,25.7.10.4=(25.4).70=100.70=7000

c,8.12.125.2=(8.125).12.2=100.24=2400

d,4.36.25.50=(4.25).(2.50).18=100.100.18=180000

c) 8 . 12 . 125

= (125 . 8) . 12

= 1000 . 12

= 12 000

d) 4 . 36 . 25 . 50

= (25 . 4) . (50 . 36)

= 100 . 1800

= 180 000

Chúc bạn học tốt!! ^^