Question

Tìm đa thức A trong mỗi đẳng thức sau:

a, (5²-13x+6):A = (5x-3):(2x+5)

b, (x²-3x):(2x²-7x+3) = (x²+4x):A

Answer 1

a: \(\Leftrightarrow\dfrac{5x^2-13x+6}{A}=\dfrac{5x-3}{2x+5}\)

\(\Leftrightarrow\dfrac{5x^2-10x-3x+6}{A}=\dfrac{5x-3}{2x+5}\)

\(\Leftrightarrow A=\dfrac{\left(2x+5\right)\left(x-2\right)\left(5x-3\right)}{\left(5x-3\right)}=\left(2x+5\right)\left(x-2\right)\)

b: \(\Leftrightarrow\dfrac{x\left(x+4\right)}{A}=\dfrac{x\left(x-3\right)}{\left(x-3\right)\left(2x-1\right)}=\dfrac{x}{\left(2x-1\right)}\)

=>A=(x+4)(2x-1)