Tìm x thuộc N biết:
X+245=43×11
X-382=159:3
7×X+2×X=918
3×(X-2)+150=240
(X+13):5=12
360:(X-7)=90
Tìm x thuộc N,biết:
a) x+245=43.11
b) x-382=159:3
c)7x+2x=918
d)3.(x-2)+150=240
a)x+245=43.11
x+245=473
x=473-245
x=228
b) x-382=159:3
x-382=53
x=53+382
x=435
k mk nhe
c) 7x+2x=918
x.(7+2)=918
x.9=918
x=918:9
x=102
Các bạn ơi giúp mình với gấp lắm rồi
1.(250+x:24-15)*7=3600
2.729:(32+x-435)=150:15
3.(245:5+x-15):14-5=5
4.502-x+37-13=46+27
5.847+x*6-382=615+42
6.743-27*18-x+38:2-27=18
7.530+48-x+38:2-27=18*12
8.618+x*(386-248:4)=15846
1.Tính
a) 7.[ 6 : 2 - 15 :(-3) - l-3l ]
b) 159.(18-59) - 59 .(18-159)
2.Tìm x thuộc Z
a) x + 15 = 20 -4x
b) 3 - lx - 1l =0
c) 7(x-3) - 5 (3-x) = 11x - 5
d) 2. lx-6l + 7x - 2 = lx-6l + 7x
1.Tính
a) 7.[ 6 : 2 - 15 :(-3) - l-3l ]
= 7.[ 3 + 5 - 3]
= 7.[( 3 - 3 ) + 5]
= 7.[0 + 5]
= 7.5
= 35
b) 159.(18-59) - 59 .(18-159)
= 159 . ( - 41) - 59 . ( - 141 )
= ( - 6519 ) - ( - 8319 )
= 1800
2.Tìm x thuộc Z
a) x + 15 = 20 -4x
x+4x=20-15
5x=5
x=5:5
x=1
Vậy x=1
b) 3 - lx - 1l =0
|x-1|=3
* x-1=3 * x-1=-3
x=3+1 x=-3+1
x=4 x=-2
Vậy x=4 hoặc x=-2
c) 7(x-3) - 5 (3-x) = 11x - 5
7x-21-15+5x=11x-5
-21-15+5=11x-7x-5x
-31=-x
31=x
Vậy x=31
5^x . 5^x+1 . 5^x+2 < 100..........0 : 2^24 ( có 24 số ko )
tìm x ( x thuộc N )
5x.5x+1.5x+2<100.................00:224
Có 24 số 0
53x.51.52<1024:2224
53x.53<524
53x<524:53
53x<521
=>3x=21
x=21:3
x=7\(\in\)N
Vậy x=7
Chúc bn học tốt
Bài 1: Tìm x nguyên, biết:
a) x + 5 = 20 - (12 -7)
b)15 - (3+ 2x) = 22
c) -11 - (19 - x) = 50
d)159 - (25 - x) = 43
e) (79 - x) - 43 = - (17 - 52)
f) (7 + x) - (21 - 13) = 32
g) - x + 20 = (-15) + 8 + 13
h) - (-x + 13 -142) + 18 = 55
Xin cảm ơn!
a) \(x+5=20-\left(12-7\right)\)
\(\Rightarrow x+5=20-5\)
\(\Rightarrow x+5=15\)
\(\Rightarrow x=15-5\)
\(\Rightarrow x=10\)
b) \(15-\left(3+2x\right)=2^2\)
\(\Rightarrow3+2x=15-4\)
\(\Rightarrow3+2x=11\)
\(\Rightarrow2x=11-3\)
\(\Rightarrow2x=8\)
\(\Rightarrow x=\dfrac{8}{2}\)
\(\Rightarrow x=4\)
c) \(-11-\left(19-x\right)=50\)
\(\Rightarrow19-x=-11-50\)
\(\Rightarrow19-x=-61\)
\(\Rightarrow x=61+19\)
\(\Rightarrow x=80\)
d) \(159-\left(25-x\right)=43\)
\(\Rightarrow25-x=159-43\)
\(\Rightarrow25-x=116\)
\(\Rightarrow x=25-116\)
\(\Rightarrow x=-91\)
e) \(\left(79-x\right)-43=-\left(17-52\right)\)
\(\Rightarrow\left(79-x\right)-43=52-17\)
\(\Rightarrow79-x-43=35\)
\(\Rightarrow36-x=35\)
\(\Rightarrow x=1\)
f) \(\left(7+x\right)-\left(21-13\right)=32\)
\(\Rightarrow7+x-8=32\)
\(\Rightarrow x-1=32\)
\(\Rightarrow x=32+1\)
\(\Rightarrow x=33\)
g) \(-x+20=-15+8+13\)
\(\Rightarrow-x+20=6\)
\(\Rightarrow x=20-6\)
\(\Rightarrow x=14\)
h) \(-\left(-x+13-142\right)+18=55\)
\(\Rightarrow x-13+142+18=55\)
\(\Rightarrow x+147=55\)
\(\Rightarrow x=55-147\)
\(\Rightarrow x=-92\)
7.x + 2.x = 927. 3(x-2)+150=240
( x + 13 ) : 5 = 120. 360:(x-7)=90
7.x + 2.x = 927
\(\Leftrightarrow\)( 7 + 2).x =927
\(\Leftrightarrow\)9.x = 927
\(\Leftrightarrow\)x = 927 : 9
\(\Leftrightarrow\)x = 103
Vậy x = 103
3(x-2)+150=240
\(\Leftrightarrow\)3(x-2)=240-150
\(\Leftrightarrow\)3(x-2)=90
\(\Leftrightarrow\)x-2=90:3
\(\Leftrightarrow\)x-2=30
\(\Leftrightarrow\)x=30+2
\(\Leftrightarrow\)x=32
Vậy x=32
( x + 13 ) : 5 = 120
\(\Leftrightarrow\)x + 13 = 120 \(\times\)5
\(\Leftrightarrow\)x + 13 = 600
\(\Leftrightarrow\)x = 600 - 13
\(\Leftrightarrow\)x = 587
Vậy x = 587
360:(x-7)=90
\(\Leftrightarrow\)x-7=360:90
\(\Leftrightarrow\)x-7=40
\(\Leftrightarrow\)x=40+7
\(\Leftrightarrow\)x=47
Vậy x=47
7.x + 2.x = 927
x.(7 + 2) = 927
x.9 = 927
x = 927 : 9
x = 103
Vậy x = 103
3(x - 2) + 150 = 240
3(x - 2) = 240 - 150
3.(x - 2) = 90
x - 2 = 90 : 3 = 30
x = 30 + 2 = 32
Vậy x = 32
(x + 13) : 5 = 120
x + 13 = 120 x 5 = 600
x = 600 - 13 = 587
Vậy x = 587
360:(x - 7) = 90
x - 7 = 360 : 90 = 4
x = 4 + 7 = 11
Vậy x = 11
Ủng hộ mk nha !!! ^_^
a) -12+(x-9)<0 tìm x thuộc Z
b)x-(13-x)=-24+(-7+x)
c) (x - 7)+( 5-x)=12-(-8+x)
d)5(x-6)-2(x+3)=12
e)3(x-4)-(8-x)=12
f) 7(x-3)-5(3-x)=11x-5
g) 7(x-9)-5(6-x)=-6+11x
a) -12+(x-9)<0 tìm x thuộc Z
b)x-(13-x)=-24+(-7+x)
c) (x - 7)+( 5-x)=12-(-8+x)
d)5(x-6)-2(x+3)=12
e)3(x-4)-(8-x)=12
f) 7(x-3)-5(3-x)=11x-5
g) 7(x-9)-5(6-x)=-6+11x
tìm x thuộc N biết
\(3^x+3^{x+3}=84\)
\(7^{x+2}+7^x=245\)
\(3^x\left(1+27\right)=84\)
\(3^x.28=84\)
\(3^x=3\)
\(x=1\)
b) \(7^x\left(49+1\right)=245\)
\(7^x.50=245\)
\(7^x=4,9\) => không có x nào thỏa mãn