tim x biết
(10-x).42=12
315+(125-x)=500
(11-x).(4-x).(5-x)
Tim x
a, ( - 14 - x ) + 13 = 5
b, ( 11 + x ) - ( - 11 - 9 ) = 32
c, 5 - ( x - 8 ) + ( - 21 ) = 42
d, - [ 4 - 15 ] - ( - 4 - x = - 45
e, - 23 - ( 10 - x ) = - 50
\(a.-14-x=-8\)
\(x=-6\)
\(b.11+x+20=32\)
\(31+x=32\)
\(x=1\)
\(c.5-\left(x-8\right)=63\)
\(x-8=-58\)
\(x=-50\)
a,\(\left(-14-x\right)+13=5\)
\(\Rightarrow-x+1=5\)
\(\Rightarrow-x=4\)
\(\Rightarrow x=-4\)
b,\(\left(11+x\right)-\left(-11-9\right)=32\)
\(\Rightarrow11+x+11+9=32\)
\(\Rightarrow x+31=32\)
\(\Rightarrow x=1\)
c,\(5-\left(x-8\right)+\left(-21\right)=42\)
\(\Rightarrow5-x+8-21=42\)
\(\Rightarrow-x-8=42\)
\(\Rightarrow x=-50\)
Bài 1 : Tìm y:
a) y - ( -42 - 2y ) = ( -12 ) - 14 + 2y
b) 15 - ( - y + 5 ) - 5y = - ( 12+ 5y)
c) 2y - ( -5 + 8y - 21 ) = -3 - ( 5y + 2 )
e) - 13 - ( - 3y - 23 ) = - ( 120 - y )
g) - 21 - ( -32 - 5y ) = - ( - 16 - 4y )
Bài 2 :
a) ( - 5 ) x 6 + 15 x 6
b) 9 x ( - 3 ) + 9 x 23
c) ( -10) x 11 + 210 x 11
d) 125 x 4 - 125 x (-4)
a) => y+42+2y= -12-14+2y
y+2y-2y = -12-14-42
y= -68
b) => 15+y-5-5y= -12-5y
y-5y+5y= -12-15+5
y = -22
c) => 2y+5-8y+21= -3-5y-2
2y-8y+5y= -3-2-5-21
-y= -31=>y=31
d)=> -13+3y+23= -120+y
3y-y= -120+13-23
2y= -130=>y= -65
e) => -21+32+5y= 16+4y
5y-4y= 16+21-32
y= 5
bài 1
a)y-(-42-2y) = (-12) - 14 +2y
y +42 + 2y = -12 -14 +2y
3y + 42 = -26 +2y
y = -68
b)15-(-y+5)-5y=-(12+5y+2)
15+y-5-5y=-12-5y-2
10-4y=-14-5y
-4y+5y=-14-10=-24
c)2y-(-5+8y-21)=-3-(5y+2)
2y+5-8y+21=-3y-5y-2
-6y+26=-8y-2
-6y+8y=-2-26
2y=-28
y=-28/2=-14
Bài 1 : Tìm y:
a) y - ( -42 - 2y ) = ( -12 ) - 14 + 2y
b) 15 - ( - y + 5 ) - 5y = - ( 12+ 5y)
c) 2y - ( -5 + 8y - 21 ) = -3 - ( 5y + 2 )
e) - 13 - ( - 3y - 23 ) = - ( 120 - y )
g) - 21 - ( -32 - 5y ) = - ( - 16 - 4y )
Bài 2 :
a) ( - 5 ) x 6 + 15 x 6
b) 9 x ( - 3 ) + 9 x 23
c) ( -10) x 11 + 210 x 11
d) 125 x 4 - 125 x (-4)
Bài 2:
a: =6(15-5)=6*10=60
b: =9(-3+23)=9*20=180
c: =11(-10+210)=11*200=2200
d: =125*4+125*4=125*8=1000
Tìm x, biết:
2/3: x/5 +5/7=2/7:3/5+10/9
A: x= 225/42
B: x = 11/42
C: 45/42
D: 42/11
\(\frac{2}{3}:\frac{x}{5}+\frac{5}{7}=\frac{2}{7}:\frac{3}{5}+\frac{10}{9}\)
\(\Rightarrow\frac{2}{3}:\frac{x}{5}+\frac{5}{7}=\frac{2}{7}.\frac{5}{3}+\frac{10}{9}\)
\(\Rightarrow\frac{2}{3}:\frac{x}{5}+\frac{5}{7}=\frac{10}{21}+\frac{10}{9}\)
\(\Rightarrow\frac{2}{3}:\frac{x}{5}+\frac{5}{7}=\frac{100}{63}\)
\(\Rightarrow\frac{2}{3}:\frac{x}{5}=\frac{100}{63}-\frac{5}{7}\)
\(\Rightarrow\frac{2}{3}:\frac{x}{5}=\frac{55}{63}\)
\(\Rightarrow\frac{x}{5}=\frac{2}{3}:\frac{55}{63}\)
\(\Rightarrow\frac{x}{5}=\frac{2}{3}.\frac{63}{55}\)
\(\Rightarrow\frac{x}{5}=\frac{42}{55}\)
\(\Rightarrow x=\frac{42.5}{55}=\frac{42}{11}\)
Nên ta chọn đáp án D là đáp án đúng!
( trong bài có dấu . tức là dấu dấu nhân bn nhé )
2/3 : x/5 + 5/7 = 2/7 : 3/5 + 10/9
2/3 : x/5 + 5/7 = 10/21 + 10/9
2/3 : x/5 + 5/7 = 100/63
2/3 : x/5 = 100/63 - 5/7
2/3 : x/5 = 55/63
2/3 . 5/x= 55/63
=) 5/x = 55/63 : 2/3
=) 5/x = 55/42
ta có : a/b = c/d =) a.d=b.c
(=) 55.x = 5.42
55.x = 210
=) x = 210 : 55 = 42/11
vậy đáp án đúng là D
chúc bn học tốt
bai 1 : tim x E n biet
a ( 9 + 8 )x + 16 . 2x = 98
b 37.5 mu x - 12. 5 mu x = ( 125 mu 2 )mu 3
c [27 + 5(x - 4 ) ] chia het cho 9
d 90 chia het cho x, 150 chia het cho x va 5<x<30
e x chia het 48, x chia het 36 va x< 500
f x chia het 60, x chia het 42, va 840<x<2500
g 45 chia het 2x + 1
h ( x +16 ) chia het ( x +15 )
k ( 2 x + 7 ) chia het ( x - 1 )
m ( 3x + 27 ) chia het (2x + 3)
n 326 chia cho x du 11 con 553 chia x du 13
traa loi nhanh cho minh , minh can gap vao dem thu sau ngay 8 thang 11
Bài 1
a)(9+8)x + 16 . 2x = 98
17x + 32x = 98
49x = 98
x = 98 : 49
x = 2
A,3^3. x-3^4=2^5-5
B,(2^3+2^1). x+3^2.x?5-10=10^2
C,(2^x+1)^3.2^2=500
D,(7x-11)^3=32.5^2+200
E,5.(3x-2)^2-3^3:3^2=2
F,(x-5)^19=16.( x-5)^6
G,4^x+80=3^yy
Tim x va y thuoc N
Câu 1: Thực hiện phép tính: 90:{9-130 - (15-10) }
A.
В. 3
C. 4
D. 5
Câu 2: Thực hiện phép tính: 3º5 : 393 – 12021 2020
A. 7
В.
C.
D. 10
Câu 3: Tim x biết 2x - 10 = 210
А. 100
В. 110
C. 120
D. 130
Câu 4: Tim x biết : 125 – 12(x-8) = 5 :5I 2022 2021
A. 19
В. 20
С. 5
D. 18
Câu 5: Thực hiện phép tính: (2021-2025) +11".11:11" -20°
A. 136
В. 140
C. 144
D. 150
tim x
a, x-5)^4 =( x-5)^6
b,(x +2) ^5 =2^10
c,5^x :5^2 =125
d, (3x - 2^4) .7^3 =2 . 7^4
b) (x+2)5=210 c) 5x : 52 = 125 d) (3x-24) . 73= 2x74 ( câu a khá dài nên mình để sau nhé )
(x+2)5=45 5x : 52 = 53 (3x-24) . 73= 2x74 : 73
x+2=4 5x = 53 . 52 3x-24 = 2x7
x=4-2 5x = 55 3x -16 =14
x=2 x = 5 3x=14+16
3x=30
x=30:3
x=10
a) (x-5)4 = (x-5)6
(x-5)4 - (x-5)6 =0
(x-5)4 - (x-5)4 . (x-5)2 =0
(x-5)4 - [ 1- (x-5 )2 ] =0
TH1: ( x-5 )4 =0 TH2: 1-( x-5)2 = 0
x-5=0 (x-5)2 = 1-0
x=0+5 (x-5)2 =1
x=5 x-5 = +-1
* x-5=1
x=6
* x-5=-1
x=4
4 x 25 - 12 x 5 + 170 : 10
( 7 + 3 mũ 3 : 3 mũ 2 ) x 4 - 3
12 : {400 :[ 500 - ( 125 + 25 x 7 )]}
168 + { [ 2 x (2 mũ 4 + 3 mũ 2 ) - 256 mũ 0 ] : 7 mũ 2
a) 4.25-12.5+170:10
=100-60+17
=40+17
=57
b) (7+33:32).4-3
=(7+3).4-3
=10.4-3
=40-3
=37
c) 12:{400:[500-(125+25.7)]}
=12:{400:[500-(125+175)]}
=12:{400:[500-300]}
=12:{400:200}
=12:2
=6
d) 168+{[2.(24+32)-2560]:72}
=168+{[2.(16+9)-1]:49}
=168+{[2.25-1]:49}
=168+{[50-1]:49}
=168+{49:49}
=168+1
=169