-3/4:(x+1)+5/2=175%–12/5
Bài 1 : a, (-175)-123+3+175+(-3)
b, 17 . 85+15 .17 -150
c, 176: ( 4. 5 mũ 2 - 3 . 2 mũ 2 )
Bài 2 : Tìm số nguyên x biết :
a,8-x = -12
b, 20 +2 mũ 3 . x = 5 mũ 2 . 4
c, 2 | x -1 | +5 =15
1)
a) \(\left(-175\right)-123+3+175+\left(-3\right)\)
\(=\left[\left(-175\right)+175\right]+\left[3+\left(-3\right)\right]-123\)
\(=0+0-123\)
\(=-123\)
b) \(17.85+15.17-150\)
\(=17.\left(85+15\right)-150\)
\(=17.100-150\)
\(=1700-150\)
\(=1550\)
c) \(176:\left(4.5^2-3.2^2\right)\)
\(=176:\left(4.25-3.4\right)\)
\(=176:\left(100-12\right)\)
\(=176:88\)
\(=2\)
2)
a) \(8-x=-12\)
\(\Rightarrow x=8-\left(-12\right)\)
\(\Rightarrow x=8+12\)
\(\Rightarrow x=20\)
Vậy \(x=20\)
b) \(20+2^3.x=5^2.4\)
\(\Rightarrow20+8.x=25.4\)
\(\Rightarrow20+8.x=100\)
\(\Rightarrow8.x=100-20\)
\(\Rightarrow8.x=80\)
\(\Rightarrow x=80:8\)
\(\Rightarrow x=10\)
Vậy \(x=10\)
c) \(2\left|x-1\right|+5=15\)
\(\Rightarrow2\left|x-1\right|=15-5\)
\(\Rightarrow2\left|x-1\right|=10\)
\(\Rightarrow\left|x-1\right|=10:2\)
\(\Rightarrow\left|x-1\right|=5\)
Xét trường hợp 1: \(x-1=5\)
\(\Rightarrow x=5+1\)
\(\Rightarrow x=6\)
Xét trường hợp 2: \(x-1=-5\)
\(\Rightarrow x=\left(-5\right)+1\)
\(\Rightarrow x=-5+1\)
\(\Rightarrow x=-\left(5-1\right)\)
\(\Rightarrow x=-4\)
Vậy \(x=6\) hoặc \(x=-4\)
Bài 1:
\(a)\left(-175\right)-123+3+175+\left(-3\right)\)
\(=\left[\left(-175\right)+175\right]+\left[\left(-3+3\right)\right]-123\)
\(=0+0-123\)
\(=-123\)
\(b)17.85+15.17-150\)
\(=17.\left(85+15\right)-150\)
\(=17.100-150=1700-150=1550\)
\(c)176:\left(4.5^2-3.2^2\right)\)
\(=176:\left(4.25-3.4\right)\)
\(=176:\left(100-12\right)=176:88=2\)
Bài 2:
\(a)8-x=-12\)
\(\Rightarrow x=8-\left(-12\right)\)
\(\Rightarrow x=20\)
\(b)20+2^3.x=5^2.4\)
\(\Rightarrow20+8.x=25.4\)
\(\Rightarrow20+8.x=100\)
\(\Rightarrow8.x=100-20\)
\(\Rightarrow8.x=80\)
\(\Rightarrow x=80:8=10\)
\(c)2\left|x-1\right|+5=15\)
\(\Rightarrow2\left|x-1\right|=15-5\)
\(\Rightarrow2\left|x-1\right|=10\)
\(\Rightarrow\left|x-1\right|=10:2\)
\(\Rightarrow\left[{}\begin{matrix}x-1=5\\x-1=-5\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=6\\x=-4\end{matrix}\right.\)
Bài 1 : Tính nhanh :
a, 2/3 + 3/4 + 4/5 + 12/9 + 28/6 + 48/15.
b, 3/5 + 4/7 + 2/8 + 10/25 + 9/21 + 28/16 ;
c , 8/7 + 7/6 + 5/8 + 10/12 + 24/28 + 6/16 ;
d, ( 1 + 1/2 ) x ( 1 + 1/3) x ( 1 + 1/4 ) x...x ( 1 + 1/175)
b, 3/5 + 4/7 + 2/8 + 10/25 + 9/21 + 28/16
= 3/5 + 4/7 + 2/8 + 2/5 + 3/7 + 14/8
= (3/5 + 2/5) + ( 4/7 + 3/7) + ( 2/8 + 14/8)
= 1 + 1 + 7/4
= 2 + 7/4 = 15/4
c , 8/7 + 7/6 + 5/8 + 10/12 + 24/28 + 6/16
= c , 8/7 + 7/6 + 5/8 + 5/6 + 6/7 + 1/2
= (8/7 + 6/7) + (7/6 + 5/6) + 5/8 + 1/2
= 14/7 + 12/6 + 5/8 + 1/2
= 2 + 2 + 5/8 + 1/2
= 4 + 9/8 = 41/8
Tìm x :
a) 13 - 2 ( x + 1 ) = 7
b) 6x + 2 . 4 = 5^2 . 2
c) 420 + 65 . 4 = ( x + 175 ) : 5 + 30
d) 32 . 12 : 2 = ( x + 70 ) : 14 - 40
e) 231 - ( x - 6 ) = 1339 : 13
f) 10 + 2x = 4^5 : 4
g) 70 - 5 ( x - 3 ) = 45
a)13-2(x+1)=7
2.(x+1)=13-7
2.(x+1)=6
x+1=6/2
x+1=3
x=3-1
x=2
a, 13 - 2 ( x + 1 ) = 7
2 .( x + 1 ) = 13 - 7
2 .( x + 1 ) = 6
x + 1 = 6 : 2
x + 1 = 3
x = 3 - 1
x = 4
b)6x+2.4=52.2
6x+2=50
6x=48
x=8
c)420+65.4=(x+175):5+30
(x+175):5+30=680
(x+175):5=650
x+175=3250
x=3075
a, 6 . 3x + 4 . 3x+1 = 100 + (-72)
b, 5 . 5x + 4 . 5x+1 = (-12) + 175 + (-38)
Các bạn giúp mình nhé.
a, => 3^x.(6+4.3) = 100-72
=> 3^x.18 = 18
=> 3^x = 18:18 = 1
=> 3^x = 3^0
=> x=0
b, => 5^x.(5+4.5) = -12+175-38
=> 5^x.25 = 125
=> 5^x = 125:25 = 5
=> 5^x = 5^1
=> x=1
Tk mk nha
a) \(6\cdot3^x+4\cdot3^{x+1}=100+\left(-72\right)\)
\(\Leftrightarrow6\cdot3^x+4\cdot3^x\cdot3=100-72\)
\(\Leftrightarrow6\cdot3^x+12\cdot3^x=28\)
\(\Leftrightarrow18\cdot3^x=28\Leftrightarrow3^x=\frac{14}{9}\)
Phần a) bn xem lại đề bài nhé!!
b) \(5\cdot5^x+4\cdot5^{x+1}=\left(-12\right)+175+\left(-38\right)\)
\(\Leftrightarrow5^{x+1}+4\cdot5^{x+1}=175-12-38\)
\(\Leftrightarrow5\cdot5^{x+1}=125\Leftrightarrow5^{x+1}=25\)
\(\Leftrightarrow5^{x+1}=5^2\Leftrightarrow x+1=2\Leftrightarrow x=1\)
Vậy x=1
câu 1 : Thực hiện phép tính
1) 2 mũ 3 .15 - [115-(12-5) mũ 2]
2) 30:{175:[355- (135+37.5)]}
câu 2 :tìm x ,biết
1)0128-3(x+4)=23
2) 720:[41-(2x-50]=2 mũ 3 .5
các bạn ơi giúp mình với tính:4 mũ 3 : 16 +(175:5 mũ 2-9^3:3^5) +12
\(4^3:16+\left(175:5^2-9^3:3^5\right)+12\)
\(=4^3:4^2+\left(175:25-3^6:4^5\right)+12\)
\(=4+\left(7-3\right)+12\)
\(=4+4+12\)
\(=8+12\)
\(=20\)
X + 56 x 2 - [ 32+16 x3 : 6-15 ] = 0
420 +65 x 4 =[ X +175 ] : 5 +30
X - 4867 = [ 175 x 2050 x 70 ] : 25 +23
2436 : x =12
Tìm x
1) I 3x - 7 I = 2
2) ( 5x - 10 )2 = 100
3) ( -4x + 5 )3 = -27
4) 2004( x - 1 ) ( x + 2 ) = 1
5) 4 ( x + 5 ) + x + 20 = -500
6) 3( x + 15 ) + 2( x + 5 ) = - 175
7) 2( 7 - x ) + 5( 14 - x ) = -136
a/ (ghi lại cái đề)
=>+ 3x-7=2
3x=2+7=9
x=3
+ 3x-7=-2
3x=-2+7=5
x=\(\frac{5}{3}\)
b/ (5x-10)2=100
=> +5x-10=10
5x=10+10=20
x=4
+ 5x-10=-10
5x=-10+10=0
x=0
a/ x=3 và 5/3
b/ (5x-10)2=100
=> +5x-10=10
5x=10+10=20
x=4
+ 5x-10=-10
5x=-10+10=0
x=0
c/(-4x+5)3=-27
-4x+5=-3
-4x=-8
x=2
Bài 1.Tìm x
d,175+(30-x)=200
e,5(x+12)+22=92
f,95-5(x+2)=45
\(\left(d\right)30-x=200-175\)
\(30-x=25\)
\(x=5\)
\(\left(e\right)5\left(x+12\right)=70\)
\(x+12=14\)
\(x=2\)
tương tự 2 câu trên bạn tự làm câu cuối nhé, mình không ghi lại đề đâu
#quankun^^
d,175+(30-x)=200
(30-x) = 200 - 175
30 - x = 25
x = 30 - 25
x = 5.
e,5(x+12)+22=92
5(x+12) = 92 - 22
5(x+12) = 70
x+12 = 70 : 5
x + 12 = 14
x = 14 - 12
x = 2.
f,95-5(x+2)=45
5(x+2) = 95 - 45
5(x+2)= 50
x + 2 = 50 : 5
x + 2 = 10
x =10 -2
x = 8
Hok tốt !
\(d,175+\left(30-x\right)=200\Leftrightarrow175+30-x=200\Leftrightarrow x=5\)
\(e,5\left(x+12\right)+22=92\Leftrightarrow5x+60+22=92\)
\(\Leftrightarrow5x=10\Leftrightarrow x=2\)
\(f,95-5\left(x+2\right)=45\Leftrightarrow95-5x-10=45\Leftrightarrow5x=40\)\(\Leftrightarrow x=8\)
#Học tốt