Toán Lớp 8: sắp xếp và làm phép chia:(-x^3+2x^4-4-x^2+7x):(x^2+x-1)
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: sắp xếp và làm phép chia:(-x^3+2x^4-4-x^2+7x):(x^2+x-1)
Comments ( 2 )
\left( { – {x^3} + 2{x^4} – 4 – {x^2} + 7x} \right)\\
= 2{x^4} – {x^3} – {x^2} + 7x – 4\\
= 2{x^4} + 2{x^3} – 2{x^2} – 3{x^3} – 3{x^2} + 3x\\
+ 4{x^2} + 4x – 4\\
= 2{x^2}\left( {{x^2} + x – 1} \right) – 3x\left( {{x^2} + x – 1} \right) + 4\left( {{x^2} + x – 1} \right)\\
= \left( {2{x^2} – 3x + 4} \right)\left( {{x^2} + x – 1} \right)\\
\Leftrightarrow \left( { – {x^3} + 2{x^4} – 4 – {x^2} + 7x} \right):\left( {{x^2} + x – 1} \right)\\
= \left( {2{x^2} – 3x + 4} \right)\left( {{x^2} + x – 1} \right):\left( {{x^2} + x – 1} \right)\\
= 2{x^2} – 3x + 4
\end{array}$