\(n_{FeSO_4}=\dfrac{22,8}{56+32+16.4}=0,15(mol)\)

Chọn B

\(n_{FeSO_4}=\dfrac{22,8}{152}=0,15\left(mol\right)\)

=> B

= 52 nha em

Đề không rõ ràng. Bạn xem lại.

\(56+44=100\)

\(44+56=100\)

56 + 44 = 100

44 + 56 = 100

56+44=100

44+56=100

k mk nhak

Love

a) \(56^2+44^2+2.56.44=56^2+2.56.44+44^2=\left(56+44\right)^2=100^2=10000\)

b) \(36^2+64^2+72.64=36^2+2.36.64+64^2=\left(36+64\right)^2=100^2=10000\)

c) \(136^2+36^2-72.136=136^2-2.36.136+36^2=\left(136-36\right)^2=100^2=10000\)

a) $56^2+44^2+2.56.44=56^2+2.56.44+44^2=\left(56+44\right)^2=100^2=10000$562+442+2.56.44=562+2.56.44+442=(56+44)2=1002=10000

b) $36^2+64^2+72.64=36^2+2.36.64+64^2=\left(36+64\right)^2=100^2=10000$362+642+72.64=362+2.36.64+642=(36+64)2=1002=10000

c) $136^2+36^2-72.136=136^2-2.36.136+36^2=\left(136-36\right)^2=100^2=10000$

-3/7+15/26-(2/13-3/7)

= -3/7+15/26-2/13+-3/7

= -(3/7+ -3/7)+(15/26-2/13)

= 0 +11/26

= 11/26

mơm bạn nha

\(3\left|4x-1\right|-2=19\)

\(3\left|4x-1\right|=21\)

\(\left|4x-1\right|=7\)

⇔\(\left[{}\begin{matrix}4x-1=7\\4x-1=-7\end{matrix}\right.\) 

⇔\(\left[{}\begin{matrix}x=2\\x=-\dfrac{3}{2}\end{matrix}\right.\)

\(\Rightarrow\left|4x-1\right|=21:3=7\\ \Rightarrow\left[{}\begin{matrix}4x-1=7\\4x-1=-7\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=2\\x=-\dfrac{3}{2}\end{matrix}\right.\)

\(3.\left|4x-1\right|-2=19\)

<=> \(\left[{}\begin{matrix}3.\left(4x-1\right)-2=19\left(x\ge\dfrac{1}{4}\right)\\3.\left[-\left(4x-1\right)\right]-2=19\left(x< \dfrac{1}{4}\right)\end{matrix}\right.\)

<=> \(\left[{}\begin{matrix}12x-3-2=19\\3.\left(-4x+1\right)-2=19\end{matrix}\right.\)

<=> \(\left[{}\begin{matrix}x=2\left(TM\right)\\x=-\dfrac{3}{2}\left(TM\right)\end{matrix}\right.\)

    (286,86 - 76,3 ) : 2,8 + 38,24

= 210,56 : 2,8 + 38,24 

= 75,2 + 38,24

= 113,44