Tìm x , biết:
a) (102−15)−(15−x)=6
b) −154+(x−9−18)=40
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a) x−(−15)=−13−(−85−13)
=> x+15=85
=>x=70
b) (−9−x)+(x−14)=17−(−8+x)
=>-9-x+x-14=17+8-x
=>-23=25-x
=>x=48
b: \(\Leftrightarrow x-15-27-x+x-13=-1\)
\(\Leftrightarrow x-55=-1\)
hay x=54
\(a,159-\left(25-x\right)=43\)
\(\Leftrightarrow25-x=195-43\)
\(\Leftrightarrow25-x=152\)
\(\Leftrightarrow x=25-152\)
\(\Leftrightarrow x=-127\)
\(b,\left(79-x\right)-43=-\left(17-25\right)\)
\(\Leftrightarrow\left(79-x\right)-43=8\)
\(\Leftrightarrow79-x=8+43\)
\(\Leftrightarrow79-x=51\)
\(\Leftrightarrow x=79-51\Rightarrow x=28\)
\(-\left(-x+13-142\right)+18=55\)
\(\Leftrightarrow-\left(-x+13-142\right)=55-18\)
\(\Leftrightarrow-\left(-x+13-142\right)=37\)
\(\Leftrightarrow x+13-142=37\)
\(\Leftrightarrow x=37+142-13\)
\(\Leftrightarrow x=166\)
\(d,\left(102-15\right)-\left(15-x\right)=6\)
\(\Leftrightarrow87-\left(15-x\right)=6\)
\(\Leftrightarrow15-x=87-6\)
\(\Leftrightarrow15-x=81\Rightarrow x=15-81\)
\(\Leftrightarrow x=-66\)
a, 2.3\(x+1\) + 38 = 23.52
2.3\(^{x+1}\) + 38 = 200
2.3\(^{x+1}\) = 200 - 38
2.3\(^{x+1}\) = 162
3\(^{x+1}\) = 162 : 2
3\(^{x+1}\) = 81
3\(^{x+1}\) = 34
\(x+1\) = 4
\(x\) = 3
b, 2\(^{x+1}\) + 4.2\(^x\) = 3.25
2\(^x\).(2 + 4) = 96
2\(^x\).6 = 96
2\(^x\) = 96 : 6
2\(^x\) = 16
2\(^x\) = 24
\(x\) = 4
\(a,\left(x-8\right)\left(x^3+8\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x-8=0\\x^3+8=0\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=8\\x^3=-8\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=8\\x=-2\end{matrix}\right.\)
\(b,\left(4x-3\right)-\left(x+5\right)=3\left(10-x\right)\\ \Leftrightarrow4x-3-x-5=30-3x\\ \Leftrightarrow3x-8-30+3x=0\\ \Leftrightarrow6x-38=0\\ \Leftrightarrow x=\dfrac{19}{3}\)
TK
`a.(x-8)(x+8)=0`
`⇔³{x−8=0x³+8=2 `
`⇔³³{x=8x³=−2³ `
`⇔{x=8x=−2`
Vậy ` x = 8;-2`
`b. ( 4 x − 3 ) − ( x + 5 ) = 3 . ( 10 − x )`
`⇔ 4 x − 3 − x − 5 = 30 − 3 x`
`⇔ 3 x − 8 = 30 − 3 x`
`⇔ 3 x + 3 x = 30 + 8`
`⇔ 6 x = 38`
`⇔ x = 19/ 3`
Vậy ` x = 19/ 3`
a) (102 − 15) − (15 − x) = 6
102 − 15 − 15 + x = 6
x = 6 − 102 + 15 + 15
x = −66.
b) −154 + (x − 9 − 18) = 40
−154 + x − 9 – 18 = 40
x = 40 + 154 + 9 + 18
x = 221.
giải thích câu a hộ mình dòng 3 chưa hiểu :)