Question

tính tổng các đơn thức -1/2x^2y; 3/4xy^2; 2/5x^2y; x^2y

mình cần gấp.

Answer 1

Ta có: \(-\dfrac{1}{2}x^2y+\dfrac{3}{4}xy^2+\dfrac{2}{5}x^2y+x^2y\)

\(=\left(-\dfrac{1}{2}+\dfrac{2}{5}+1\right)x^2y+\dfrac{3}{4}xy^2\)

\(=\left(-\dfrac{5}{10}+\dfrac{4}{10}+\dfrac{10}{10}\right)x^2y+\dfrac{3}{4}xy^2\)

\(=\dfrac{9}{10}x^2y+\dfrac{3}{4}xy^2\)