Tìm x biết 9 + x = 2
A. 7
B. -7
C. 11
D. -11
Bài 1 : Tìm số nguyên x biết :
a, 11 - ( 15 + 11 ) = x - ( 25 - 9 )
b, 2 - x = 17 - ( - 5 )
c, x - 12 = ( - 9 ) - 15
d, 9 - 25 = ( 7 - x ) - ( 25 + 7 )
a, 11 - ( 15 + 11 ) = x - ( 25 - 9 )
11-15-11=x-25+9
-15=x-16
x=1
b, 2 - x = 17 - ( - 5 )
2-x=22
x=-20
c, x - 12 = ( - 9 ) - 15
x-12=-24
x=-12
d, 9 - 25 = ( 7 - x ) - ( 25 + 7 )
(7-x)-32=-16
7-x=16
x=-9
#H
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
Bài 2
a) tính: 2/7×-2/11+2/7÷-11/9
b) tìm x,biết -1/3+7/8÷x=1/3
Bài 1: Tìm số Nguyên x biết:
A,x-12=(-9)-15
B,2-x=17-(-5)
C,11-(15+11)=x-(25-9)
D,x-(17-x)=x-7
E,9-25=(7-x)-(25+7)
G,x-13=21-x
Giúp mình với mình cần gấp lắm!!!
a) Ta có: \(x-12=\left(-9\right)-15\)
\(\Rightarrow x-12=-24\)
\(\Rightarrow x=-12\)
b) \(2-x=17-\left(-5\right)\)
\(\Rightarrow2-x=22\)
\(\Rightarrow x=2-22\)
\(\Rightarrow x=-20\)
c) \(11-\left(15+11\right)=x-\left(25-9\right)\)
\(\Rightarrow-15=x-16\)
\(\Rightarrow x=1\)
d) \(x-\left(17-x\right)=x-7\)
\(\Rightarrow x-17+x=x-7\)
\(\Rightarrow x+x-x=-7+17\)
\(\Rightarrow x=10\)
e) \(9-25=\left(7-x\right)-\left(25+7\right)\)
\(\Rightarrow9-25=7-x-25-7\)
\(\Rightarrow-16=-25-x\)
\(\Rightarrow x=-9\)
g) \(x-13=21-x\)
\(\Rightarrow x+x=21+13\)
\(\Rightarrow2x=34\)
\(\Rightarrow x=17\)
a, x - 12 = ( -9 ) - 15
x - 12 = -24
x = -24 + 12
x = -12
b, 2 - x = 17 - ( -5 )
2 - x = 22
x = 2 - 22
x = -20
c, 11 - ( 15 + 11 ) = x - ( 25 - 9 )
11 - 26 = x - 16
-15 = x - 16
x = -15 + 16
x = 1
d, x - ( 17 - x ) = x - 7
x - 17 + x = x - 7
x + x - 17 = x - 7
x + x - x = -7 + 17
x = 10
e.9 - 25 = ( 7- x ) - ( 25 + 7 )
-16 = ( 7 - x ) -32
7 - x = -32 + 16
7 - x = 16
x = 7 - 16
x= -9
g, x - 13 = 21 - x
x + x = 21 + 13
2x = 44
x = 44 : 2
x=22
tìm x
a) 39/7 : X =13
b) 2/3 . X + 1/2 = 1/10
c) X : 8/11 = 11/3
d) 2/9 - 7/8 . X = 1/3
\(a,\frac{39}{7}:x=13\)
\(x=\frac{39}{7}:13=\frac{3}{7}\)
\(b,\frac{2}{3}\cdot x+\frac{1}{2}=\frac{1}{10}\)
\(\frac{2}{3}.x=\frac{1}{10}-\frac{1}{2}=-\frac{2}{5}\)
\(x=-\frac{2}{5}:\frac{2}{3}=-\frac{3}{5}\)
\(c,x:\frac{8}{11}=\frac{11}{3}\)
\(x=\frac{11}{3}\cdot\frac{8}{11}=\frac{8}{3}\)
\(d,\frac{2}{9}-\frac{7}{8}\cdot x=\frac{1}{3}\)
\(\frac{7}{8}.x=\frac{2}{9}-\frac{1}{3}=-\frac{1}{9}\)
\(x=-\frac{1}{9}:\frac{7}{8}=-\frac{8}{63}\)
cảm ơn Ngyễn Thị Ngọc Ánh nha bạn lm đúng mà mình k nhầm xl bạn nhìu
\(\(a,\frac{39}{7}:x=13\) \(x=\frac{39}{7}:13=\frac{3}{7}\) \(b,\frac{2}{3}\cdot x+\frac{1}{2}=\frac{1}{10}\) \(\frac{2}{3}.x=\frac{1}{10}-\frac{1}{2}=-\frac{2}{5}\) \(x=-\frac{2}{5}:\frac{2}{3}=-\frac{3}{5}\) \(c,x:\frac{8}{11}=\frac{11}{3}\)\)
\(\(x=\frac{11}{3}\cdot\frac{8}{11}=\frac{8}{3}\) \(d,\frac{2}{9}-\frac{7}{8}\cdot x=\frac{1}{3}\) \(\frac{7}{8}.x=\frac{2}{9}-\frac{1}{3}=-\frac{1}{9}\) \(x=-\frac{1}{9}:\frac{7}{8}=-\frac{8}{63}\) \)
Tính bằng 2 cách:
a, ( 6/11 + 5/11 ) x 3/17
b, 3/5 x 7/9 - 3/5 x 2/9
c, ( 6/7 - 4/7 ) : 2/5
d, 8/15 : 2/11 + 7/15 : 2/11
a, (6/11+5/11)x3/17
c1:=1x3/17
=3/17
c2:=6/11x3/17+5/11x3/17
=18/197+15/187
=33/187
=3/17
b,3/5x7/9-3/5x2/9
c1:=21/45-6/45
=15/45
=1/3
c2:=3/5x(7/9-2/9)
=3/5x5/9
=1/3
c,( 6/7-4/7):2/5
c1:=2/7:2/5
=2/7x5/2
=5/7
c2,6/7:2/5-4/7:2/5
=6/7x5/2-4/7x5/2
=15/7-10/7
=5/7
d,8/15:2/11+7/15:2/11
c1:=(8/15+7/15):2/11
=1x11/2
=11/2
c2:=8/15x11/2+7/15x11/2
=88/30+77/30
=165/30
=11/2
a) (\(\frac{6}{11}\) + \(\frac{5}{11}\)) x \(\frac{3}{17}\)= \(\frac{11}{11}\) x \(\frac{3}{17}\)= \(1\) x\(\frac{3}{17}\)= \(\frac{3}{17}\)
b) \(\frac{3}{5}\)x\(\frac{7}{9}\)- \(\frac{3}{5}\)x \(\frac{2}{9}\) = \(\frac{3}{5}\)x (\(\frac{7}{9}\)- \(\frac{2}{9}\))= \(\frac{3}{5}\) x \(\frac{5}{9}\)= \(\frac{3}{9}\)
c) (\(\frac{6}{7}\)- \(\frac{4}{7}\)) : \(\frac{2}{5}\)= \(\frac{2}{7}\) x \(\frac{5}{2}\)= \(\frac{5}{7}\)
d) \(\frac{8}{15}\) : \(\frac{2}{11}\) + \(\frac{7}{15}\): \(\frac{2}{11}\)= ( \(\frac{8}{15}\)+ \(\frac{7}{15}\)) x \(\frac{11}{2}\)= 1 x \(\frac{11}{2}\)= \(\frac{11}{2}\)
Chúc học tốt nha!
a,3/17
b,1/3
c,5/7
d,11/2
chúc bạn hk tốt nhé(nhớ k cho tiu)
Tính bằng hai cách
a) ( 6 / 11 + 5 / 11 ) x 3 / 7
b) 3 / 5 x 7 / 9 - 3 / 5 x 2 / 9
c) ( 6 / 7 - 4 / 7 ) : 2 / 5
d) 8 / 15 : 2 / 11 + 7 / 15 : 2 / 11
nhiều thế ren giải được ma bik giải xng rồi có dc chi hông?
tìm x:
a) 11-(15+11)=x-(25-9)
b)2-x=17-(-5)
c)IxI-7=9
d)3x-40=5x+32
a)11-(15+11)=x-(25-9)
11-26=x-16
-15=x-16
x=-15+16
x=1
vậy x=1
b)2-x=17-(-5)
2-x=22
x=2-22
x=-24
vậy x=-24
c)lxl-7=9
lxl=9+7
lxl=16
=>x=+-16
vậy x=+-16
d)3x-40=5x+32
3x-5x=40+32
(3-5)x=72
-2x=72
x=72:(-2)
x=-36
vậy x=-36
a) 11 - ( 15 + 11 ) = x - ( 25 - 9 )
=> x - ( 25 - 9 ) = 11 - ( 15 + 11 )
x - 16 = 11 - 26
x - 16 = -15
x = -15 + 16
x = 1
Vậy x = 1
b) 2 - x = 17 - ( -5 )
2 - x = 22
x = 2 - 22
x = -20
Vậy x = -20
c) | x | - 7 = 9
| x | = 9 + 7
| x | = 16
=> x = 16 hoặc -16
Vậy x = 16 hoặc -16
d) 3x - 40 = 5x + 32
=>3x - 5x = 40 + 32
x( 3 - 5 ) = 72
x . ( - 2 ) = 72
x = 72 : ( -2 )
x = -36
Vậy x = -36
tìm x
a) 4/5.x=4/7
b) x:8/11=11/3
c) 4/5+5/7:x=1/6
d) 2/9-7/8.x=1/3
a) 4/5.x=4/7
=>x=4/7:4/5
=>x=4/7.5/4
=>x=5/7
b) x:8/11=11/3
=>x=11/3.8/11
=>x=8/3
c)4/5+5/7:x=1/6
=>5/7:x=1/6-4/5
=>5/7:x=-19/30
=>x=5/7:(-19/30)
=>x=-150/133
d)2/9-7/8.x=1/3
=>7/8.x=2/9-1/3
=>7/8.x=-1/9
=>x=-1/9:7/8
=>x=-8/63
nhớ đ-ú-n-g nha
Tìm x:( áp dungj quy tắc chuyển vế để làm )
a)2-x=17-(-5)
b)11-(15+11)=x-(25-9)
c)9-25=(7-x)-(25+7)
d)x-(17-x)=x-7
e)3x + 26 =5
\(a,2-x=17-\left(-5\right)\)
\(\Rightarrow2-x=17+5\)
\(\Rightarrow2-x=22\)
\(\Rightarrow x=2-22\)
\(\Rightarrow x=-20\)
Vay...
\(b,11-\left(15+11\right)=x-\left(25-9\right)\)
\(\Rightarrow11-26=x-16\)
\(\Rightarrow-15=x-16\)
\(\Rightarrow-15+16=x\)
\(\Rightarrow x=1\)
\(c,9-25=\left(7-x\right)-\left(25+7\right)\)
\(\Rightarrow-16=7-x-32\)
\(\Rightarrow-16=-x-25\)
\(\Rightarrow x=-25+16\)
\(\Rightarrow x=-9\)
Vay \(x=-9\)