caau nayf laf caau tim x nha
\(a,\left(x-15\right)\times100=0\)
\(x-15=0\)
\(x=0+15\)
\(x=15\)
\(b,64\times\left(x-10\right)=128\)
\(x-10=128\div64\)
\(x-10=2\)
\(x=2+10\)
\(x=12\)
\(c,x-105\div21=15\)
\(x-5=15\)
\(x=15+5\)
\(x=20\)
\(d,\left(x-105\right)\div21=15\)
\(x-105=15\times21\)
\(x-105=315\)
\(x=315+105\)
\(x=420\)
\(d,315+\left(125-x\right)=435\)
\(125-x=435-315\)
\(125-x=120\)
\(x=125-120\)
\(x=5\)
Học tốt
a) (x -15) *100 =0 b) 64* (x- 10 )= 128 c) x- 105 :21 =15 e) 315 + ( 125 - x) = 435
(x -15) = 0: 100 (x- 10) = 128: 64 x - 105 = 15. 21 ( 125 - x ) = 435 - 315
( x -15) = 0 ( x- 10) = 2 x - 105 = 315 ( 125 - x) = 120
x = 0+ 15 x = 10 +2 x = 315 + 105 x = 125 - 120
x =15 x = 12 x = 420 x =5
(x-15)=0:100
(x-15)=0
x=0+15
x=15
vậy x=15
(x-10)=128:64
(x-10)=2
x=2+10
x=12
vậy x=12
x-105=15×21
x-105=315
x=315+105
x=420
vậy x=420
(x-105)=15×21
(x-105)=315
x=315+105
x=420
vậy x=420
(125-x)=435-315
(125-x)=120
x=125-120
x=5
vậy x=5
câu c mình sai
x-5=15
x=15+5
x=20
vậy x=20
a, \(\left(x-15\right).100=0\Leftrightarrow x-15=0\Leftrightarrow x=15\)
b, \(64\left(x-10\right)=128\Leftrightarrow64x-640=128\)
\(\Leftrightarrow64x=768\Leftrightarrow x=12\)
c, \(x-105:21=15\Leftrightarrow x-5=15\Leftrightarrow x=20\)
d, \(\left(x-105\right):21=15\Leftrightarrow x-105=315\Leftrightarrow x=420\)
e, \(315+\left(125-x\right)=435\Leftrightarrow440-x=435\Leftrightarrow x=5\)
Bài 1. Viết gọn các tích sau bằng cách dùng lũy thừa:
a) 5.5.5.5.5.5.5.5
b) 10.10.10.5.2
c) 3.3.3.5.5.5.5
d) 100.10.10.10.10.10
