Question

Cho biết:
\(A=\dfrac{2x+1}{4x-2}+\dfrac{1-2x}{4x+2}-\dfrac{2}{1-4x^2}\)

a. Rút gọn A.
b. Tính giá trị A khi x=0,25

Answer 1

\(a,A=\dfrac{4x^2+4x+1-4x^2+4x-1+4}{2\left(2x-1\right)\left(2x+1\right)}=\dfrac{4\left(2x+1\right)}{2\left(2x-1\right)\left(2x+1\right)}=\dfrac{2}{2x-1}\\ b,x=0,25=\dfrac{1}{4}\Leftrightarrow A=\dfrac{2}{2\cdot\dfrac{1}{4}-1}=\dfrac{2}{-\dfrac{1}{2}}=-4\)