Tìm x biết 4x - 5(7+x) = -15
A. x=−20
B. x=15
C.x=20
D. x=65
Những câu hỏi liên quan
Tìm x, biết:a)
1230
:
3
(
x
-
20
)
10
b)
250
-
10
(
24
-
3
x
)
:
15
244
c)
4
x
3
+
15
47
d)
65
-
4
x
+
2...
Đọc tiếp
Tìm x, biết:
a) 1230 : 3 ( x - 20 ) = 10
b) 250 - 10 ( 24 - 3 x ) : 15 = 244
c) 4 x 3 + 15 = 47
d) 65 - 4 x + 2 = 2014 0
e) 4 . 2 x - 3 = 125
Tìm x, biết:a, 1230 : 3(x – 20) 10b, 250 – 10.(24 – 3x):15 244c,
4
x
3
+ 15 47d,
65
-
4
x
+
2
2014
0
e,
4...
Đọc tiếp
Tìm x, biết:
a, 1230 : 3(x – 20) = 10
b, 250 – 10.(24 – 3x):15 = 244
c, 4 x 3 + 15 = 47
d, 65 - 4 x + 2 = 2014 0
e, 4 . 2 x - 3 = 125
a, 1230 : 3(x – 20) = 10
3(x – 20) = 123
x – 20 = 41
x = 61
b, 250 – 10.(24 – 3x):15 = 244
10.(24 – 3x):15 = 6
10.(24 – 3x) = 90
24 – 3x = 9
3x = 15
x = 5
c, 4 x 3 + 15 = 47
4 x 3 = 32
x 3 = 8 = 2 3
x = 2
d, 65 - 4 x + 2 = 2014 0
65 - 4 x + 2 = 1
4 x + 2 = 64 = 4 3
x + 2 = 3
x = 1
e, 4 . 2 x - 3 = 125
4 . 2 x = 128
2 x = 32 = 2 5
x = 5
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tìm x,biết
5-x-16=40+x
4x-10=15-x
15-x=4x-5
x-15=6+4x
-12+x=5x-20
7x-4=20+3x
5x-7=-21-2x
x+15=20-4x
17-x=7-6x
5-x-16=40+x
-x-x=40+16-5
(-x).2=51
-x=51/2=>x=51/2
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15-x = 4x -5
15 + 5 = 4x + x
5x = 20
x= 4
x - 15 = 6 + 4x
-15 - 6 = 4x -x
3x = -21
x= -7
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Xem thêm câu trả lời
a, x+15=20-4x
b,17-x=7-6x
c,-12+x=5x-20
d,4x-5=15-x
e,9x-7=20-6x
g,2.(x-10=3.(x-20=x-4
h,(x^2+2).(x-3) <0
a) x+15 = 20-4x
=> x=1
b) 17-x=7-6x
=> x=-2
c) -12+x=5x-20
=> x=2
d) 4x-5=15-x
=> x=4
e) 9x-7=20-6x
=>x= \(\frac{9}{5}\)
g)2.(x-10)=3.(x-20)=x-4
=> x thuộc ∅
h) (x^2+2).(x-3) <0
=> x=3,...
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a) -12+x=5x-20
b) 4x-10=15-x
c) 7x-4=20+3x
d) 3x-6=5x+2
e) 5x-7=-21-2x
f) 15-x=4x-5
g) x+15=20-4x
a) -12+x=5x-20
-12+x -5x = -20
-12+ ( -4x) = -20
-4x= -20-(-12)
-4x=-8
x= -8: (-4)
x= 2
Vậy....
Ko chắc nha
b) 4x-10=15-x
4x-10 +x=15
5x -10=15
5x= 15+10
5x= 25
x=25:5
x=5
Vậy...
c) 7x-4=20+3x
7x -4 - 3x= 20
4x -4= 20
4x= 20+4
4x= 24
x= 24:4
x=6
Vậy...
Xem thêm câu trả lời
tìm x a, \(\dfrac{x}{4}\) =\(\dfrac{15}{20}\) b, \(\dfrac{15}{x}\) = \(\dfrac{25}{35}\) c, \(\dfrac{x}{5}\)=\(\dfrac{26}{65}\) d, \(\dfrac{3}{x}\)=\(\dfrac{51}{85}\)
\(a,\dfrac{x}{4}=\dfrac{15}{20}\\ \Rightarrow\dfrac{x}{4}=\dfrac{3}{4}\\ \Rightarrow x=3\\ b,\dfrac{15}{x}=\dfrac{25}{35}\\ \Rightarrow\dfrac{15}{x}=\dfrac{5}{7}\\ \Rightarrow\dfrac{15}{x}=\dfrac{15}{21}\\ \Rightarrow x=21\\ c,\dfrac{x}{5}=\dfrac{26}{65}\\ \Rightarrow\dfrac{x}{5}=\dfrac{2}{5}\\ \Rightarrow x=2\\ d,\dfrac{3}{x}=\dfrac{51}{85}\\ \Rightarrow\dfrac{3}{x}=\dfrac{3}{5}\\ \Rightarrow x=5\)
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a,x4=1520⇒x4=34⇒x=3b,15x=2535⇒15x=57⇒15x=1521⇒x=21c,x5=2665⇒x5=25⇒x=2d,3x=5185⇒3x=35⇒x=5
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Tìm x € Z biết
a: -2x -40= (5-x)- (-15+ 60)
b: 2.(x-5)- 3.(x+7) =14
c: 3.(x-4)-( 8-x)=12
d: 4.( x-5)- (x+7) =-19
e: x+18= 6-2x
f: x+5= 20-4x
g: -12+ x= 5x-20
1Tìm x biết
a,x+15=20-4x
b,17-x=7-6x
c,4.(x-5)-3.(x+7)= -19
d,-7.(5-x)-2.(x-10)=15
e,-5.(2-x)+4.(x-3)=10.x-15
ai làm nhanh nhất mình sẽ tích cho
a, x+15=20-4x
=> x + 4x = 20 - 15
=> 5x = 5
=> x = 5 : 5
=> x = 1
b, 17-x=7-6x
=> -x + 6x = 7 - 17
=> 5x = - 10
=> x = -10 : 5
=> x = -2
c, 4.(x-5)-3.(x+7)= -19
=> 4x - 4.5 - 3.x + 3.7 = -19
=> 4x - 20 - 3x + 21 = -19
=> (4x-3x) + (21-20) = -19
=> 1x + 1 = -19
=> x = -19 - 1
=> x = -18
d, -7.(5-x)-2.(x-10)=15
=> -7x - (-7).5 - 2x - 2.10 = 15
=> -7x - (-35) - 2x - 20 = 15
=> -7x + 35 - 2x - 20 = 15
=> -7x+2x + (35-20) = 15
=> -5x + 15 = 15
=> -5x = 15 - 15
=> -5x = 0
=> x = 0 : (-5)
=> x = 0
e, -5.(2-x)+4.(x-3) = 10.x-15
=> -5x - (-5).2 + 4x - 4.3 = 10x - 15
=> -5x - (-10) + 4x - 12 = 10x - 15
=> -5x + 10 + 4x - 12 = 10x - 15
=> (-5x+4x) - (12-10) = 10x - 15
=> -1x - 2 = 10x - 15
=> -1x - 10x = -15 + 2
=> -11x = -13
=> x = \(\frac{-13}{-11}\)
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Tìm x, biết:a)
4
x
+
18
:
2
13
b)
2
x
-
2
0
3
5
:
3
3
c)
48
-
3
(
x
+
5
)
24
d)
(
15
+
x
)
:
3
3...
Đọc tiếp
Tìm x, biết:
a) 4 x + 18 : 2 = 13
b) 2 x - 2 0 = 3 5 : 3 3
c) 48 - 3 ( x + 5 ) = 24
d) ( 15 + x ) : 3 = 3 15 : 3 12
Tìm x, biết:a, 4x+18:2 13b, 48 – 3(x+5) 24c,
2
x
-
2
0
3
5
:
3
3
d, (15+x):3
3
15
:
3
12
Đọc tiếp
Tìm x, biết:
a, 4x+18:2 = 13
b, 48 – 3(x+5) = 24
c, 2 x - 2 0 = 3 5 : 3 3
d, (15+x):3 = 3 15 : 3 12
a, 4x+18:2 = 13
4x+9 = 13
x = 1
b, 48 – 3(x+5) = 24
3(x+5) = 24
x + 5 = 8
x = 3
c, 2 x - 2 0 = 3 5 : 3 3
2x – 1 = 3 2
2x = 10
x = 5
d, (15+x):3 = 3 15 : 3 12
(15+x):3 = 3 3
(15+x):3 = 27
15 + x = 54
x = 39
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