Tìm x
A, ( x - 3 ) ^2 = (-3)^2 + (-4)^2
B, -12 × ( x -5 ) + 7 × ( 3-x) = 5
C, 30 × ( x + 2) -6 × ( x-5 ) - 24 × x = 100
tìm x, biết:
a. - 12 . ( x - 5) + 7 . ( 3 - x ) =5
b. 30 .( x+ 2 ) - 6 . ( x- 5) -24 .x = 100
c. ( x - 1 ) . ( x mũ 2 + 1) = 0
d. - 12 .( x-5) + 7 . (3- x) =5
a/ \(-12\left(x-5\right)+7\left(3-x\right)=5\)
\(< =>-12x+60+21-7x=5\)
\(< =>-19x+81=5\)
\(< =>-19x=-76\)
\(< =>x=\frac{76}{19}\)
b/ 30(x+2)-6(x-5)-24x=100
<=>30x + 60 - 6x + 30 - 24x =100
<=> 90=100( vô lý)
c/ \(\left(x-1\right)\left(x^2+1\right)=0\)
\(< =>\hept{\begin{cases}x-1=0\\x^2+1=0\end{cases}}< =>\hept{\begin{cases}x=1\\x^2=-1\left(voly\right)\end{cases}}\)
d/ làm rồi mà
a. \(-12.\left(x-5\right)+7.\left(3-x\right)=5\)
\(-12x+60+21-7x=5\)
\(-19x+81=5\)
\(-19x=-76\)
\(x=4\)
b. \(30.\left(x+2\right)-6.\left(x-5\right)-24x=100\)
\(30x+60-6x+30-24x=100\)
\(\left(30x-6x-24x\right)+\left(60+30\right)=100\)
\(90=100\)(vô lí)
\(\Rightarrow x=\varnothing\)
c. \(\left(x-1\right)\left(x^2+1\right)=0\)
\(\Rightarrow\orbr{\begin{cases}x-1=0\\x^2+1=0\end{cases}\Rightarrow\orbr{\begin{cases}x=1\\x^2=-1\left(loại\right)\end{cases}}}\)
\(\Rightarrow x=1\)
Câu d) chính là câu a) :D
a) - 12 . ( x - 5) + 7 . ( 3 - x ) =5
-12x-(-60)+21-7x=5
-12x+60+21-7x=5
-12x-7x=5-60-21
-19x=-76
19x=76
x=76:19
x=4
vậy x=4
b) 30 .( x+ 2 ) - 6 . ( x- 5) -24 .x = 100
30x-60-6x+30-24x=100
(30x-6x-24x)+(60+30)=100
90=100 (vô lí)
vậy \(x\in\varnothing\)
c) ( x - 1 ) . ( x 2+ 1) = 0
* x-1=0 * x2+1=0
x=0+1 x2=0-1
x=1 x2=-1 ( vô lí ,x2 \(\ge0\))
a,-12(x-5)+7(3-x)=5
b,-12x-(-12).5+7.3-7.x=5
c,30(x+2)-6(x-3)-24.x=100
a) \(-12\left(x-5\right)+7\left(3-x\right)=5\)
\(-12x+60+21-7x=5\)
\(-19x=5-60-21\)
\(-19x=-76\)
\(x=4\)
vậy \(x=4\)
tương tự
Bài toán 3 : Tìm x, biết.
a. 2(x – 5) – 3(x + 7) = 14 b. 5(x – 6) – 2(x + 3) = 12
c. 3(x – 4) – (8 – x) = 12 d. -7(3x – 5) + 2(7x – 14) = 28
e. 5(3 – 2x) + 5(x – 4) = 6 – 4x f. -5(2 – x) + 4(x – 3) = 10x – 15
g. 2(4x – 8) – 7(3 + x) = |-4|(3 – 2) h. 8(x – |-7|) – 6(x – 2) = |-8|.6 – 50
k. -7(5 – x) – 2(x – 10) = 15 l. 4(x – 1) – 3(x – 2) = -|-5|
m. -4(x + 1) + 89x – 3) = 24 n. 5(x – 30 – 2(x + 6) = 9
o. -3(x – 5) + 6(x + 2) = 9 p. 7(x – 9) – 5(6 – x) = – 6 + 11x
q. 10(x – 7) – 8(x + 5) = 6.(-5) + 24
nhiều quá :((
\(a,2\left(x-5\right)-3\left(x+7\right)=14\)
\(2x-10-3x-21=14\)
\(-x-31=14\)
\(-x=45\)
\(x=45\)
\(b,5\left(x-6\right)-2\left(x+3\right)=12\)
\(5x-30-2x-6=12\)
\(3x-36==12\)
\(3x=48\)
\(x=16\)
\(c,3\left(x-4\right)-\left(8-x\right)=12\)
\(3x-12-8+x=0\)
\(4x-20=0\)
\(4x=20\)
\(x=5\)
Cố nốt nha bn !
cảm ơn, bn nha:)))
mà hình như bạn TOP 3 trả lời câu hỏi pải ko nhỉ???
d, \(-7\left(3x-5\right)+2\left(7x-14\right)=28\)
\(\Leftrightarrow-21x+35+14x-28=28\Leftrightarrow-7x=21\Leftrightarrow x=-3\)
e, \(5\left(3-2x\right)+5\left(x-4\right)=6-4x\)
\(\Leftrightarrow15-6x+5x-20=6-4x\Leftrightarrow-5-x=6-4x\)
\(\Leftrightarrow-11+3x=0\Leftrightarrow x=\frac{11}{3}\)
f, \(-5\left(2-x\right)+4\left(x-3\right)=10x-15\)
\(\Leftrightarrow-10+5x+4x-12=10x-15\Leftrightarrow-22+9x=10x-15\)
\(\Leftrightarrow-7-x=0\Leftrightarrow x=-7\)
tìm x biết:
a)-12(x-5)+7(3-x)=5
b)30(x+2)-6(x-5)-24=100
a, => -12x+60+21-7x=5
=> 71-19x=5
=> 19x = 71-5 = 66
=> x = 66 : 19 = 4
b, => 30x+60-6x+30-24=100
=> 24x+76 = 100
=> 24x = 100-76 = 24
=> x = 24 : 24 = 1
Tk mk nha
a, -12x-(-60)+21-7x=5
-19x+81=5
-19x=5-81
-19x=-76
x=-4
b, 30(x+2)-6(x-5)-24=100
30x+60-6x+30-24=100
36x+76=100
36x=34
x=34/36
Tìm x :
a, -12 ( x - 5 ) + 7 ( 3 - x ) = 5
b, 30 ( x + 2 ) - 6 ( x - 5 ) - 24 . x =100
a. -12.(x-5)+7.(3-x)=5
=> -12x+60+21-7x=5
=> -19x+81=5
=> -19x=5-81
=> -19x=-76
=> x=(-76):(-19)
=> x=4
b. 30.(x+2)-6.(x-5)-24.x=100
=> 30x+60-6x+30-24x=100
=> (30x-6x-24x)+(60+30)=100
=> 0x+90=100
=> 0x=100-90
=> 0x=10 (vô lí)
=> không tồn tại x.
tìm x biết
a, -12.(x-5) +7 . (3-x) = 5
b, 30.(x+2) - 6 .(x-5) - 24.x = 100
c, | 2x-5| = 13
d, (x+1) + ( x+3) + (x+5) +.....+(x+99) = 0
-12.(x - 5) + 7.(3 - x) = 5
-12x + 60 + 21 - 7x = 5
-12x - 7x = 5 - 60 - 21
-19x = -76
x = -76 : (-19)
x = 4
Vậy x = 4
Tìm x biết
a) 2.(x-5) = -24
b) 2. (x-5) -7= 13
c) 5.(3-x)+2. (x-7) = -14
d) 12. (x-5)+ 7. (3-x) = 5
e) 30. (x+2) - 6.(x-5) -24.x = 160
1,Tìm X thuộc Z sao cho
(x-7).(x+3)<0
2,tìm x
a,-12.(x-5)-7.(3-x)=5
b,30.(x-2)-6.(x-5)-24.x=100
cả nhà giúp mình vs
TÌM X THUỘC Z
a , -12 x ( X - 5 ) + 7 x ( 3 - X ) = 5
b , 30 x ( X +2 ) - 6 x ( X - 5 ) - 24 x X =100