Tìm x thuộc N biết :
a) 4x - x = 138 b) 123 -5 * ( x + 4 ) = 38
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
b) 123 - 5.(x+4) = 38
=> 5.(x+4) = 123 - 38
=> 5.(x+4) = 85
=> (x+4) = 85 : 5
=> x+4 = 17
=> x = 17 - 4
=> x = 13
c) 2.x - 138 = 23.32
=>2.x - 138 = 736
=>2.x = 736 + 138
=>2.x = 874
=> x = 874 : 2
=> x = 437
d) 70 - 5.(x-3) = 45
=> 5.(x-3) = 70 - 45
=> 5.(x-3) = 25
=> (x-3) = 25 : 5
=> x-3 = 5
=> x = 5 + 3
=> x = 8
a,219-7(x+1)=100
7(x+1)=219-100
7(x+1)=119
x+1= 119:7
x+1= 17
x= 17-1
x=16
Vậy x=16
b,123-5.(x+40)=38
5.(x+40)=123-38
5.(x+40)=85
x+40= 85:5
x+40=17
x= 17-40
x=-23
Vậy x=-23
c,(3x-6).3=34
3x-6 =34:3
3x-6 =33
3x-6 =27
3x =27+6
3x =33
x =33:3
x =11
Vậy x=11
d, 42.x=39.42-37.42
42.x=1638-1554
42.x=84
x =84:42
x =2
Vậy x=2
Nhớ nhé, học giỏi ^^
a,
128-3x-12=23
3x=128-12-23
3x=93
x=93:3
= 31
b,
(12x+84+55):5=35
12x+84+55=35.5
12x+84+55=175
12x=175-55-84
12x=36
x=36:12
x=3
a) \(3x-18.28:14=308\)
\(=>3x-36=308\)
\(=>3x=344\)\(\)
\(=>x=\frac{344}{3}\)
\(\)b)\(38+\left|x\right|=\left(-12\right)+65\)
\(=>38+\left|x\right|=53=>\left|x\right|=15=>\orbr{\begin{cases}x=15\\x=-15\end{cases}}\)
c)\(15+3.\left(x-1\right):5=30\)
\(=>15+3.\left(x-1\right)=150\)
\(=>3.\left(x-1\right)=135\)
\(x-1=45=>x=46\)
d) \(5.\left(7-3x\right)+7.\left(2+2x\right)=1\)
\(=>35-15x+14+14x=1\)
\(=>49-x=1=>x=48\)
e)\(3.\left(x-7\right)=21\)
\(=>x-7=7=>x=14\)
g)\(\left[\left(6x-72\right):2-84\right]:28=5628\)
\(\left(6x-72\right):2-84=157584\)
\(\left(6x-72\right):2=157668\)
\(6x-72=315336\)
\(6x=315408=>x=52568\)
h)\(123-5\left(x+4\right)=28\)
\(5.\left(x+4\right)=95\)
\(x+4=19=>x=15\)
p)\(14.\left(x-3\right)-138=73\)
\(14.\left(x-3\right)=211\)
\(x-3=\frac{211}{14}=>x=\frac{253}{14}\)
\(t\)
\(\left|x\right|-5=2\)
\(\left|x\right|=7=>\orbr{\begin{cases}x=7\\x=-7\end{cases}}\)
v)\(4x-72=\left|100-8.25\right|\)
\(4x-72=\left|-100\right|\)
\(4x-72=100=>4x=172=>x=43\)
cậu có thể tham khảo bài làm trên đây ạ, chúc cậu học tốt ^^
123 – 5(x + 4) = 38
5(x + 4) = 123 – 38
5(x + 4) = 85
x + 4 = 85 : 5
x + 4 = 17
x = 17 – 4
x = 13
Vậy x = 13
`123-5(x+4)=38`
`5x-20=123-38`
`5x-20=85`
`5x=85+20`
`5x=105`
`x=105:5`
`x=21`
123-5.(x+4)=38
5x-20=123-38
5x-20=85
5x=85+20
5x=105
x=105:5
x=21
a) x-12=-15
x=-15+12
x=-3
b) 123-5(x+4)=38
5(x+4)=123-38
5(x+4)=85
x+4=85:5=17
x=17-4
x=13
\(a.x-12=-15\) \(b.123-5.\left(x+4\right)=38\)
\(x=\left(-15\right)+12\) \(5.\left(x+4\right)=123-38\)
\(x=-3\) \(5.\left(x+4\right)=85\)
\(x+4=85:5=17\)
\(x=17-4=13\)
a)4x-x=138
x(4-1)=138
x .3=138
x=138:3
x=46
a) 4x - x = 138
=> 3x = 138
=> x = 46
b) 123 - 5 x (x + 4) = 38
=> 5 x (x + 4) = 85
=> x + 4 = 17
=> x = 13