Toán Lớp 8: Bài 2: Cho A= $\frac{2x-1}{x^{2}-1}$ (x # ± 1)
a) Rút gọn A
b) Tính A khi x=0; x=3
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: Bài 2: Cho A= $\frac{2x-1}{x^{2}-1}$ (x # ± 1)
a) Rút gọn A
b) Tính A khi x=0; x=3
Comments ( 1 )
a)A = \dfrac{{2x – 1}}{{\left( {x – 1} \right)\left( {x + 1} \right)}}\\
b)A = 1\\
A = \dfrac{5}{8}
\end{array}\)
a)A = \dfrac{{2x – 1}}{{{x^2} – 1}} = \dfrac{{2x – 1}}{{\left( {x – 1} \right)\left( {x + 1} \right)}}\\
b)Thay:x = 0\\
\to A = \dfrac{{2.0 – 1}}{{\left( {0 – 1} \right)\left( {0 + 1} \right)}} = \dfrac{{ – 1}}{{ – 1}} = 1\\
Thay:x = 3\\
\to A = \dfrac{{2.3 – 1}}{{\left( {3 – 1} \right)\left( {3 + 1} \right)}} = \dfrac{5}{{2.4}} = \dfrac{5}{8}
\end{array}\)