30 + (x + 2) = 26
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(a,3-\left(17-x\right)=-12\\ \Rightarrow17-x=15\\ \Rightarrow x=2\\ b,-26-\left(x-7\right)=0\\ \Rightarrow x-7=-26\\ \Rightarrow x=-19\\ c,25+\left(-2+x\right)=5\\ \Rightarrow-2+x=20\\ \Rightarrow x=18\\ d,30+\left(32-x\right)=10\\ \Rightarrow32-x=-20\\ \Rightarrow x=52\)
a) `3-(17-x)=-12`
`3-17+x=-12`
`x=-12-3+17`
`x=2`
b) `-26-(x-7)=0`
`-26-x+7=0`
`-19-x=0`
`x=-19`
c) `25+(-2+x)=5`
`25-2+x=5`
`x=5-25+2`
`x=-18`
d) `30+(32-x)=10`
`30+32-x=10`
`62-x=10`
`x=52`
\(\frac{x^{30}+x^{28}+x^{26}+x^{24}+...+x^4+x^2+1}{x^{28}+x^{24}+x^{20}+...+x^8+x^4+1}=\frac{\left(x^{30}+x^{26}+x^{22}+...+x^2\right)+\left(x^{28}+x^{24}+...+x^4+1\right)}{x^{28}+x^{24}+x^{20}+...+x^4+1}\)
\(=\frac{x^2\left(x^{28}+x^{24}+...+x^4+1\right)+\left(x^{28}+x^{24}+...+x^4+1\right)}{x^{28}+x^{24}+...+x^4+1}\)
\(=\frac{\left(x^2+1\right)\left(x^{28}+x^{24}+...+x^4+1\right)}{x^{28}+x^{24}+...+x^4+1}\)
\(=x^2+1\)
\(x\cdot\left(x+1\right)-26=30\)
\(x\cdot\left(x+1\right)=30+26\)
\(x\cdot\left(x+1\right)=56\)
\(x\cdot\left(x+1\right)=7\cdot8\)
\(=>x=7\)
Trả lời:
\(x.\left(x+1\right)-26=30\)
\(\Leftrightarrow x^2+x-26=30\)
\(\Leftrightarrow x^2+x-56=0\)
\(\Leftrightarrow x^2+8x-7x-56=0\)
\(\Leftrightarrow x.\left(x+8\right)-7.\left(x+8\right)=0\)
\(\Leftrightarrow\left(x+8\right).\left(x-7\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}x+8=0\\x-7=0\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=-8\\x=7\end{cases}}\)
Vậy \(x\in\left\{-8,7\right\}\)
Học tốt
30 + (x + 2) = 26
x + 2 = 26 - 30
x + 2 = -4
x = - 4 + 2
x = -2
30 + ( x + 2 ) = 26
( x + 2 ) = 30 - 26
( x + 2 ) = 4
x = 4 - 2
x = 2