a,(6x-72):2-84=5628
=>(6x-72):2=5628+84
=>(6x-72):2=5712
=>6x-72=5712.2
=>6x-72=11424
=>6x=11424+72
=>6x=11496
=>x=11496:6
=>x=1916
b,\(\left(\dfrac{9}{2}-2x\right):75\%=1\dfrac{1}{3}\)
=>\(\left(\dfrac{9}{2}-2x\right):\dfrac{3}{4}=\dfrac{4}{3}\)
=>\(\dfrac{9}{2}-2x=\dfrac{4}{3}.\dfrac{3}{4}\)
=>\(\dfrac{9}{2}-2x=1\)
=>\(2x=\dfrac{9}{2}-1\)
=>\(2x=\dfrac{9}{2}-\dfrac{2}{2}\)
=>\(2x=\dfrac{7}{2}\)
=>\(x=\dfrac{7}{2}:2\)
=>\(x=\dfrac{7}{2}.\dfrac{1}{2}\)
=>x\(x=\dfrac{7}{4}\)
a. [(6x-72):2-84]=5628
\(\Leftrightarrow\) (6x-72):2 = 5628 + 84
\(\Leftrightarrow\) (6x-72):2 = 5712
\(\Leftrightarrow\) 6x-72 = 5712 . 2
\(\Leftrightarrow\) 6x-72 = 11424 \(\Leftrightarrow\) 6x = 11424+72 \(\Leftrightarrow\) 6x = 11496 \(\Leftrightarrow\) x = 11496:6 \(\Leftrightarrow\) x =1916 b. \(\left(\dfrac{9}{2}-2x\right):75\%=1\dfrac{1}{3}\) \(\Leftrightarrow\left(\dfrac{9}{2}-2x\right):\dfrac{3}{4}=\dfrac{4}{3}\) \(\Leftrightarrow\dfrac{9}{2}-2x=\dfrac{4}{3}.\dfrac{3}{4}\) \(\Leftrightarrow\dfrac{9}{2}-2x=1\) \(\Leftrightarrow2x=\dfrac{9}{2}-1\) \(\Leftrightarrow2x=\dfrac{7}{2}\) \(\Leftrightarrow x=\dfrac{7}{2}:2\) \(\Leftrightarrow x=\dfrac{7}{4}\)
a. [(6x-72):2-84]=5628
(6x-72):2 =5628+84
(6x-72):2 =5712
6x-72 =5712:2
6x-72 =2856
6x =2856+72
6x = 2928
x =2928:6
x = 488
Vậy x=488
b.( \(\dfrac{9}{2}\)-2x):75%=1\(\dfrac{1}{3}\)
(\(\dfrac{9}{2}\)-2x):\(\dfrac{3}{4}\) =\(\dfrac{4}{3}\)
\(\dfrac{9}{2}\)-2x = \(\dfrac{4}{3}\)×\(\dfrac{3}{4}\)
\(\dfrac{9}{2}\)-2x =1
2x =\(\dfrac{9}{2}\)-1
2x =\(\dfrac{9}{2}\)-\(\dfrac{2}{2}\)
2x =\(\dfrac{7}{2}\)
x = \(\dfrac{7}{2}\):2
x =\(\dfrac{7}{2}×\dfrac{1}{2}\)
x =\(\dfrac{7}{4}\)
Vậy x=\(\dfrac{7}{4}\)
a, [ ( 6x - 72 ) : 2 - 84 ] = 5628
( 6x - 72 ) : 2 - 84 = 5628
( 6x - 72 ) : 2 = 5628 + 84
( 6x - 72 ) : 2 = 5712
6x - 72 = 5712 . 2
6x - 72 = 11 424
6x = 11 424 + 72
6x = 11 496
x = 11 496 : 6
x = 1916 .
b, \(\left(\dfrac{9}{2}-2x\right):75\%=1\dfrac{1}{3}\)
\(\left(\dfrac{9}{2}-2x\right):\dfrac{3}{4}=\dfrac{4}{3}\)
\(\dfrac{9}{2}-2x=\dfrac{3}{4}:\dfrac{4}{3}\)
\(\dfrac{9}{2}-2x=\dfrac{12}{16}\)
......
còn lại tự làm , đến đây thì dễ rồi còn j nx !!!
Mk cho các bn gợi ý nha! Cô mk gợi ý đó!
a.x=107
b.x=\(\dfrac{7}{4}\)
Giúp mk z!
Đề a sai rùi! Sorry nha @Thái Nhữ, @Trần Thị Mỹ Bình, @Con Gái Họ Lê, @CÔNG CHÚA THẤT LẠC.
Đề đúg nè:
a.[(6x-72):2-84].28=5628
Sssooorrrrrryyy!!!
