Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a) 12 : { 390 : [ 500 - ( 125 + 35. 7 ) ] }
= 12 : { 390 : [ 500 - ( 125 + 245 ) ] }
= 12 : { 390 : [ 500 - 370 ] }
= 12 : { 390 : 130 }
= 12 : 3
= 4
200-{30-(4-1)2
=200-{30-9}
=179
12:{390:[500-(125+35*7)]}
=12: {390 : [500- 245]}
=12 : {390 : 255}
=12 : 1,52941176471
= 7.84615384613
12000-(1500*2 + 1800 * 3+1800*2:3)
=12000-(3000+5400+3600:3)
= 12000-9600
=2400
600: { 450:[450-(4*53 - 23 *52)]}
= 600:{ 450:[450-(4*125-8*25)]}
=600:{450:[450-300]}
=600: { 450: 150}
=600 : 3
= 200
\(28.76+13.28+11.28\) \(12000-\left(1500.2+1800.3+1800.2:3\right)\)
\(=28\cdot\left(76+13+11\right)\) \(=12000-9600\)
\(=28.100=2800\) \(=2400\)
Những phép sau tương tự
12 : {390 : [ 500 - (125 + 35 . 7)]}
= 12 : { 390 : [500 - 370]
= 12 : {390 : 130}
= 12 : 3
= 4
Chúc các bạn học tốt
a) 12 : { 390 : [ 500 - ( 125 + 35 x 7 ) ] }
= 12 : { 390 : [ 500 - 370 ] }
= 12 : { 390 : 130 }
= 12 : 3 = 4
b) 12000 - ( 15000 x 2 + 18000 x 3 + 18000 x 2 : 3 )
= 12000 - ( 30000 + 54000 + 12000 ) = -84000
c) 5 x { 26 - [ 3 x ( 5 + 2 x 5 ) + 15 ] : 15 }
= 5 x { 26 - [ 3 x 15 + 15 ] : 15 }
= 5 x { 26 - 60 : 15 }
= 5 x 22 = 110
b. 1500(x-7)=0
x-7=0
x=7
c. (2x-4)(48-12x)=0
2x-4=0 hoặc 48-12x=0
x=2 hoặc x=4
d. (x+12)(x-1)=0
x+12=0 hoặc x-1=0
x=-12 hoặc x=1
bài 2 :
a . 128-3(x+4)=23
3(x+4)=105
x+4=35
x=31
b. [(14X+26).3+55]:5=35
(14x+26).3+55=175
(14x+26).3=120
14x+26=40
14x=14
x=1
d. 720:[41-(2X-5)]=23.5
41-(2x-5)=720:(23.5)
41-(2x-5)=144/23
2x-5=799/23
2x=914/23
x=457/23
b, 1500.(x – 7) = 0
<=>1500x-10500=0
<=>1500x=10500
<=>x=7
Vậy x=7
c,(2.x – 4).(48 – 12.x) = 0
\(\Leftrightarrow\)\(\left\{{}\begin{matrix}2x-4=0\\48-12x=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}2x=4\\12x=48\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=2\\x=4\end{matrix}\right.\)
Vậy x=2 hoặc x=4
d, (x + 12).(x – 1) =0
\(\Leftrightarrow\left\{{}\begin{matrix}x+12=0\\x-1=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=-12\\x=1\end{matrix}\right.\)
Vậy x=-12 hoặc x=1
Bài 2:
a) 128- 3(x+ 4) = 23
\(\Leftrightarrow\)128-(3x+12)=23
\(\Leftrightarrow\)128-3x-12=23
\(\Leftrightarrow\)116-3x=23
\(\Leftrightarrow\)3x=116-23
\(\Leftrightarrow\)3x=93
\(\Leftrightarrow\)x=31
Vậy x=31
b) [(14x+ 26). 3+ 55]: 5= 35
\(\Leftrightarrow\)(14x+ 26). 3+ 55=175
\(\Leftrightarrow\)42x+78+55=175
\(\Leftrightarrow\)42x+133=175
\(\Leftrightarrow\)42x=175-133
\(\Leftrightarrow\)42x=42
\(\Leftrightarrow\)x=1
Vậy x=1
d, 720: [41- (2x- 5)]= 23. 5
\(\Leftrightarrow\)720: 41- (2x- 5)=115
\(\Leftrightarrow\)41-(2x- 5)=720:115
\(\Leftrightarrow\)41-(2x- 5)=\(\dfrac{144}{23}\)
\(\Leftrightarrow\)2x-5=\(\dfrac{799}{23}\)
\(\Leftrightarrow\)2x=\(\dfrac{914}{23}\)
\(\Leftrightarrow\)x=\(\dfrac{457}{23}\)
Vậy x=\(\dfrac{457}{23}\)
Bài 1:
a) x.x.y.y.x.y.x = \(x^4.y^3\)
b) 1000.10.10= 1000. \(10^2\)
c) \(3^{15}:3^5=3^{15-5}=3^{10}\)
d) \(9^8:3=3^{16}:3=3^{15}\)
e) \(125:5^3=\dfrac{125}{5^3}=\dfrac{5^3}{5^3}=1\)
B2:
a) 17.23+17.77
=850
b) 12000 - ( 1500 .2 + 1800 .3 +1800 .2 : 3
=2400
c) [173. ( 17 +6 ) + 137.6^7 ]: 137
=279959
d) [2^10. ( 137 - 111 ) +2^10 .84)] : 1024: 5^2
=4,4
