Toán Lớp 8: 1/(X-2)^2-x(x-1)
2/(x-4)^2-x^2=0
3/(x-4)^2-x^2=-8
Thanks ạ
Leave a reply
Register Now
Login
Lost Password
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Toán Lớp 8: 1/(X-2)^2-x(x-1)
2/(x-4)^2-x^2=0
3/(x-4)^2-x^2=-8
Thanks ạ
Comments ( 2 )
a){\left( {x – 2} \right)^2} – x\left( {x – 1} \right)\\
\Rightarrow {x^2} – 2x + 1 – {x^2} + x\\
\Rightarrow – x + 1\\
b){\left( {x – 4} \right)^2} – {x^2} = 0\\
\Rightarrow (x – 4 – x)(x – 4 + x) = 0\\
\Rightarrow – 4.(2x – 4) = 0\\
\Rightarrow 2x – 4 = 0\\
\Rightarrow x = 2\\
c){\left( {x – 4} \right)^2} – {x^2} = – 8\\
\Rightarrow \left( {x – 4 – x} \right)\left( {x – 4 + x} \right) = – 8\\
\Rightarrow 2x – 4 = 2\\
\Rightarrow 2x = 6\\
\Rightarrow x = 3
\end{array}\]
1)\\
{\left( {x – 2} \right)^2} – x\left( {x – 1} \right)\\
= {x^2} – 2x + 1 – {x^2} + x\\
= – x + 1\\
2)\\
{\left( {x – 4} \right)^2} – {x^2} = 0\\
\Leftrightarrow \left( {x – 4 – x} \right)\left( {x – 4 + x} \right) = 0\\
\Leftrightarrow – 4.\left( {2x – 4} \right) = 0\\
\Leftrightarrow 2x – 4 = 0\\
\Leftrightarrow x = 2\\
Vậy\,x = 2\\
3){\left( {x – 4} \right)^2} – {x^2} = – 8\\
\Leftrightarrow – 4.\left( {2x – 4} \right) = – 8\\
\Leftrightarrow 2x – 4 = 2\\
\Leftrightarrow 2x = 6\\
\Leftrightarrow x = 3\\
Vậy\,x = 3
\end{array}$