bằng 22

  (28+46)+(53-28-31-46)

=53-31+28-28+46-46

=53-31

=22

[ 28 + 46] + [ 53 - 28 - 31-46]=22

NHỚ NHÉ

cái này ra lẻ bạn ah

mik ghi p/s nhé

là 15 phần 28

là bao nhiêu vậy bạn

\(215-\left(-85\right)-2021^0+\left(28-100\right)-\left(28+2021\right)\)

\(=215+85-1+28-100-28-2021\)

\(=\left(215+85-100\right)-1+\left(28-28\right)-2021\)

\(=200-1+0-2021\)

\(=199-2021=-1822\)

\(B=\left(4^5\cdot10\cdot5^6+25^5\cdot2^8\right):\left(2^8\cdot5^4+5^7\cdot2^5\right)\)

\(B=\dfrac{4^5\cdot10\cdot5^6+25^5\cdot2^8}{2^8\cdot5^4+5^7\cdot2^5}\)

\(B=\dfrac{\left(2^2\right)^5\cdot2\cdot5\cdot5^6+\left(5^2\right)^5\cdot2^8}{2^8\cdot5^4+5^7\cdot2^5}\)

\(B=\dfrac{2^{11}\cdot5^7+5^{10}\cdot2^8}{2^8\cdot5^4+5^7\cdot2^5}\)

\(B=\dfrac{2^8\cdot5^7\cdot\left(2^3\cdot1+5^3\cdot1\right)}{2^5\cdot5^4\cdot\left(2^3\cdot1+5^3\cdot1\right)}\)

\(B=\dfrac{2^8\cdot5^7}{2^5\cdot5^4}\)

\(B=\dfrac{2^3\cdot5^3}{1\cdot1}\)

\(B=\left(2\cdot5\right)^3\)

\(B=10^3\)

\(B=1000\)

Đề đâu bạn nhỉ?

`2/5 + 9/15= 2/5 + 3/5=5/5=1`

`15/45 + 25/30= 1/3 + 5/6= 2/6+5/6=7/6`

`28/32 + 45/72=7/8+ 5/8=12/8=3/2`

`8/28 + 5/30= 2/7 + 1/6= 12/42 + 7/42= 19/42`