Tìm x biết
5x+25=125
tìm x biết
5x-13=17
\(\Rightarrow5x=30\)
\(\Rightarrow x=6\)
5x-13=17
5x=13+17
5x= 30
x=30:5
x=6.
Vậy x=6
tìm x biết
5x + 5x^2 = 43x^3
\(5x+5x^2=43x^3\\ \Rightarrow43x^3-5x^2-5x=0\\ \Rightarrow x\left(43x^2-5x-5\right)=0\\ \Rightarrow\left[{}\begin{matrix}x=0\\43x^2-5x-5=0\left(1\right)\end{matrix}\right.\\ \Delta\left(1\right)=25+4.5.43=885\\ \Rightarrow\left[{}\begin{matrix}x=0\\x=\dfrac{5+\sqrt{885}}{86}\\x=\dfrac{5-\sqrt{885}}{86}\end{matrix}\right.\)
tìm x biết
5x-8.15=(-21)x30
Tìm tổng các số nguyên x thỏa mãn : -103<x<100 ta đc kết quả là bao nhiêu
\(\Leftrightarrow5x=-630+120=-510\)
hay x=-102
8. Bỏ dấu ngoặc rồi tính:
a) ( 17 – 229) + ( 17 - 25 + 229) ; b) ( 125 – 679 + 145) – ( 125 – 679 )
9. Tìm x biết: a) 15 – ( 4 – x) = 6 ; b) - 30 + ( 25 – x) = - 1 ;
c) x – ( 12 – 25) = -8 ; d) ( x – 29 ) – ( 17 – 38 ) = - 9
10. Tìm số nguyên x biết: a) x – 5 = - 1 ; b) x + 30 = - 4; c) x – ( - 24) = 3 ; d) 22 – ( - x ) = 12; e) ( x + 5 ) + ( x – 9 ) = x + 2 ; f) ( 27 – x ) + ( 15 + x ) = x – 24 .
Phần tự luận
Tìm x:
x x 125 = 25
Tìm x
x3+125+(x+5)(x-25)=0
\(x^3\) + 125 + (\(x\) + 5)(\(x\) - 25) = 0
(\(x^3\) + 53) + (\(x\) + 5)(\(x\) - 25) = 0
(\(x\) + 5)(\(x^2\) - 5\(x\) + 25) + (\(x\) + 5)(\(x\) - 25) =0
(\(x\) + 5)(\(x^2\) - 5\(x\) + 25 + \(x\) - 25) = 0
(\(x\) + 5)(\(x^2\) - 4\(x\)) = 0
\(x\)(\(x\) + 5)(\(x\) - 4) = 0
\(\left[{}\begin{matrix}x=0\\x+5=0\\x-4=0\end{matrix}\right.\)
\(\left[{}\begin{matrix}x=0\\x=-5\\x=4\end{matrix}\right.\)
`x^3 + 125 + (x + 5)(x - 25) = 0`
`<=>(x + 5)(x^2 + 5x + 25) + (x + 5)(x - 25) = 0`
`<=>(x + 5)(x^2 + 6x) = 0`
`<=>x(x + 5)(x + 6) = 0`
`<=>x = 0` hoặc `x = -5` hoặc `x=-6`
Sửa:
`x^3 + 125 + (x + 5)(x - 25) = 0`
`<=>(x + 5)(x^2 - 5x + 25) + (x + 5)(x - 25) = 0`
`<=>(x+5)(x^2-4x)=0`
`<=>x(x+5)(x-4)=0`
`<=>x=0` hoặc `x=-5` hoặc `x=4`
Tìm x thỏa mãn x : 2 5 - 1 2 5 = 1
A. x = 1
B. x = -1
C. x = 5/2
D. x = -5/2
Tìm x: (x+5)+(x+10)+...+(x+25)-125=150
\(\left(x+5\right)+\left(x+10\right)+...+\left(x+25\right)-125=150\)
\(\Leftrightarrow x+5+x+10+...+x+25-125=150\)
\(\Leftrightarrow5x-50=150\)
\(\Leftrightarrow5x=100\)
\(\Leftrightarrow x=\dfrac{100}{5}=20\)
Vậy \(x=20\)
Bài kia mik làm sai r
\(\left(x+5\right)+\left(x+10\right)+...+\left(x+25\right)-125=150\)
\(\Leftrightarrow x+5+x+10+...+x+25-125=150\)
\(\Leftrightarrow5x-50=150\)
\(\Leftrightarrow5x=200\)
\(\Leftrightarrow x=\dfrac{200}{5}=40\)
Vậy \(x=40\)
Tìm x, biết : x x 125 – x x 25 = 37 800
\(x\times125-x\times25=37800\\ \Rightarrow x\times\left(125-25\right)=37800\\ \Rightarrow x\times100=37800\\ x=378\)
Tìm x:
x + x + 25 = 125
x + x + 25 = 125
ta có : 2x + 25 = 125
2x = 125 - 25
2x = 100
x = 50
k mik nha
x + x + 25 = 125
=>2x+25=125
=>2x=125-25
=>2x=100
=>x=100:2
=>x=50
k nha
x+x+25=125
x+x=125-25
x+x=100
x=100:2
x=50