\(5.\left(x+4\right)+38=123\)
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Tìm số tự nhiên \(x\) , biết :
a) \(123-5\left(x+4\right)=38\)
b) \(\left(3.x-2^4\right).7^3=2.7^4\)
a) \(123-5\left(x+4\right)=38\)
\(5\left(x+4\right)=123-38\)
\(5\left(x+4\right)=85\)
\(x+4=85:5\)
\(x+4=17\)
\(x=17-4\)
\(x=13\)
Vậy \(x=13\).
b) \(\left(3x-2^4\right)\cdot7^3=2\cdot7^4\)
\(3x-16=2\cdot7^4:7^3\)
\(3x-16=2\cdot7\)
\(3x-16=14\)
\(3x=14+16\)
\(3x=30\)
\(x=30:3\)
\(x=10\)
Vậy \(x=10\).
a: \(A=\dfrac{63-48-70}{84}:\dfrac{-3\cdot84+4\cdot60+5\cdot70}{840}\cdot\dfrac{1-14}{12}\)
\(=\dfrac{-55}{84}\cdot\dfrac{840}{338}\cdot\dfrac{-13}{12}=\dfrac{55}{1}\cdot\dfrac{10}{338}\cdot\dfrac{13}{12}=\dfrac{275}{156}\)
b: \(=-234\cdot123+123\cdot4356-123\cdot2312+234\cdot123-234\cdot2312+2312\cdot234+2312\cdot123\)
\(=123\cdot4356-123\cdot2312+123\cdot2312=123\cdot4356=535788\)
\(123-5\left(x+4\right)=38\\ 5\left(x+4\right)=85\\ x+4=17\\ x=13\)
\(123-5\left(x+4\right)=38\)
\(\Rightarrow123-5x-20=38\)
\(\Rightarrow-5x=-65\)
\(\Rightarrow x=13\)
Vậy: ...
`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
\(123-5\left(x:2+4\right)=38\\ \Rightarrow5\left(x:2+4\right)=85\\ \Rightarrow x:2+4=17\\ \Rightarrow x:2=13\\ \Rightarrow x=26.\)
\(123-5\left(x:2+4\right)=38\)
\(5\left(x:2+4\right)=123-38\)
\(5\left(x:2+4\right)=85\)
\(x:2+4=85:5\)
\(x:2+4=17\)
\(x:2=17-4\)
\(x:2=13\)
\(x=13.2\)
\(x=26\)
\(a,\left(\frac{2}{5}\right)^6.\left(\frac{25}{4}\right)^2=\left(\frac{2}{2.3}\right)^6.\left(\frac{5}{2}\right)^4\)
\(=\frac{1}{3^6}.\frac{5^4}{2^4}=\frac{5^4}{3^6.2^4}\)
\(b,\frac{100}{123}:\left(\frac{3}{4}+\frac{7}{12}\right)+\frac{23}{123}:\left(\frac{9}{5}-\frac{7}{15}\right)\)
\(=\frac{100}{123}:\left(\frac{9+7}{12}\right)+\frac{23}{123}:\left(\frac{27-7}{15}\right)\)
\(=\frac{100}{123}:\frac{16}{12}+\frac{23}{123}:\frac{20}{15}\)
\(=\frac{100.12}{123.16}+\frac{23.15}{123.20}\)
\(=\frac{5.5.4.3.4}{41.3.4.4}+\frac{23.3.5}{41.3.4.5}\)
\(=\frac{25}{41}+\frac{23}{164}=\frac{25.4+23}{164}\)
\(=\frac{123}{164}=\frac{3}{4}\)
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
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=21
5.(x+4)+38=123
5.(x+4) = 123- 38
5.(x+4) = 85
x+4 = 85:5
x+4 = 17
x = 17 -4
x = 13
vậy x=13
\(5.\left(x+4\right)+38=123\)
\(5x+20=123-38\)
\(5x+20=85\)
\(5x=65\)
x = 13
Vậy x = 13