a) -12.(x-5)+7(3-x)=15
b) 30.(x+2)-6.(x-5)-24.x=100
Tìm x
a, -12 . (x-5)+ 7 . ( 3-x ) =15
b, 30(x+20 - 6(x-5) - 24 - x =100
b, 30(x+20) - 6(x-5) - 24 - x =100
30x+600-6x+30-24-x=100
30x-6x+x=100-600-30-24
25x=-554
x=\(-\frac{554}{25}\)
cho li-ke nha
a, -12 . (x-5)+ 7 . ( 3-x ) =15
-12x+60+21-7x=15
-12x7x=15-60-21
-21x=-66
x= -544/25
tick nha
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
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, biết:
a. -12 . ( x - 5 ) + 7 . ( 3 - x ) = 15
b. 30 . ( x + 2 ) - 5 . ( x - 5 ) - 24 . x = 100
c. ( 30x + 60 ) - ( 6x - 30 ) - 24x = 100
( giải chi tiết nha )
a. -12 (x-5) +7(3-x) = -12x+60+21-7x=-19x+81=15
=> -19x=15-81=-66
=> x=66/19
b. 30(x+2) - 5 (x-5) - 24x = 30x+60-5x+25-24x =(30x-5x-24x)+(60+25)=x+85=100
=> x=100-85=15
c. ( 30x + 60 ) - ( 6x - 30 ) - 24x = 100
=30x+60-6x+30-24x
=90=100 (cô lý)
Vậy không có x thỏa mãn
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
a, -12.(x-5)+7.(3-x) = 15
b, 30-(x+2)-6.(x-5)-24x=100
a, -12(x-5)+7(3-x)=15
=> -12x+60+21-7x=15
=>-19x+81=15
=>-19x=15-81
=>-19x=....
tách ra rồi tính
tìm x:
a) -12(x-5)+7(3-x)=15
b) 30(x+2)-6(x-5)-24x=100
a/ => -12x + 60 + 21 - 7x = 15
=> -19x = -66
=> x = 66/19
b/ => 30x + 60 - 6x + 30 - 24x = 100
=> 0x = 10
=> vô nghiệm