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

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

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

a)  7 12

b) 201400

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

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

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

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

_______________

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

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

\(=2022\cdot100\)

\(=202200\)

_____________________

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

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

\(=20+19\)

\(=39\)

___________________

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

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

\(=17,58\times100\)

\(=1758\)

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

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

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

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

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

e) [(17,75 - 1,25) : 1,5 + 1] x ( 17,75 + 1,25) :2 = 114

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

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

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

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

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

d) 0

a) 19,17x25x4=19,17(25x4)=19,17x100=1917

b)1,79x(8x125)=1,79x1000=1790

chúc bạn học tốt

??????????????????????

= (8.125). (25.4).3³

=  1000. 100.9
= 100 000.9
= 900 000