a) 9x-32=31
9x=32+31
9x=63
x=63:9
x=7
b)23(450-5x)=2346
450-5x=2346:23
450-5x=102
-5x=102-450
-5x=-348
x=-348:(-5)
x=69,6
c) x:8+ 64:8=20
x:8 +8=20
x:8=20-8
x:8=12
x=12.8
x=96
d) 7.2x=112
2x=112:7
2x=16
mà 24=16
=> x=4
e) 5.4x=320
4x=320:5
4x=64
mà 43 =64
=> x=3
g) [5.(70-x)+23 .32 ] :4 =28
(350-x + 8.9) = 28.4
350-x+72=112
-x=112-350-72
-x=-310
=> x=310
a) 9x - 32 = 31
9x = 31 + 32
9x = 63
x = 63 : 9
x = 7
bạn ơi bạn cố gắng suy nghĩ và làm tiếp cho mình nhé
a)9x - 32 = 31
9x = 31+ 32
9x = 63
x = 7
b) 23 . ( 450 - 5x ) = 2346
450 - 5x = 2346 : 23
450 - 5x = 102
5x = 450 -102
5x = 348
x = 348 : 5
x = 348/5
c) x : 8 + 64 : 8 = 20
8( x + 64) = 20
x + 64 = 20 : 8
x + 64 = 5/2
x = 5/2 - 64
x = -123/2
d) 7 . 2x = 112
2x= 112 : 7
2x=16
2x=24
x=4
e)4x= 320 : 5
4x=64
x=3
g) [ 5 . (70-x) + 72]:4 = 28
[ 5 . (70-x)+72]=28:4=7
5 . (70-x)=7-72=-65
70-x=-65:5=-13
x=70-(-13)
x=83
23 . ( 450 - 5x ) = 2346
450 - 5x = 2346 : 23
450 - 5x = 102
5x = 450 - 102
5x = 348
x = 348:5
23 . ( 450 - 5x ) = 2346
450 - 5x = 2346 : 23
450 - 5x = 102
5x = 450 - 102
5x = 348
x = 348 : 5
x = 69,6