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.(x-5)+7(3-x)=15
b) 30.(x+2)-6.(x-5)-24.x=100
\(-12\left(x-5\right)+7\left(3-x\right)=15\)
\(-12x+60+21-7x=15\)
\(-12x-7x=15-60-21\)
\(-19x=-66\)
\(x=\frac{66}{19}\)
Vây....
b)
a) -12.(x-5)+7(3-x)=15
<=> - 12x + 60 + 21 - 7x = 15
<=> 12x + 7x = 60 + 21 - 15
<=> 19x = 66
<=> x = \(\frac{66}{19}\)
Vậy x = \(\frac{66}{19}\)
b) 30.(x+2)-6.(x-5)-24.x=100
<=> 30x + 60 - 6x + 30 - 24x = 100
<=> 0x = 10(vô lí)
VẬY x = \(\varnothing\)
-12.(x-5)+7(3-x)\(=\)15
\(\Leftrightarrow\) -12x+60+21-7x\(=\)15
-19x+81=15
-19x=15-81
19x=66
x=66/19
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 \(\ge0\))
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 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
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
a) \(\left(x-3\right)^2\) = \(\left(-3\right)^2\) + \(\left(-4\right)^2\)
\(\left(x-3\right)^2=9+16\)
\(\left(x-3\right)^2=25\)
\(\left(x-3\right)^2=5^2\)
\(\Rightarrow x-3=5\)
\(\Rightarrow x=5+3=8\)
Vậy x = 8
b) -12 . (x - 5) +7 . (3 - x) = 5
-12x + 60 + 21 - 7x = 5
-12x - 7x = 5 - 60 - 21
-19x = -76
x = -76 : (-19) =4
Vậy x = 4
c) 30 . (x + 2) - 6 . ( x - 5) - 24x = 100
30x + 60 - 6x + 30 - 24x =100
30x - 6x - 24x = 100 - 30 - 60
0x = 10
x=10 : 0
\(\Rightarrow x\in\varnothing\)
tìm x thuộc Z biết:
câu a:-12(-x+7).(3-x)=5
câu b:30.(x+2-6).(x-5)-24.x=100.|-9-x|=17
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 biết
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
=>-12x+60+21+7x=5
=>-12x+7x=5-60-21
=>-5x=-76
=>x=-76:-5
=>x=15,2
b,30.(x+2)-6.(x-5)-24.x=100
=>30.x+60-(6.x-30)-24.x=100
=>30.x+60-6.x+30-24x=100
=>30.x-6.x-24.x=100-60-30
=>0x=10(vô lý)
Vậy không có x thỏa mãn