toan9thd

phuong trinh kia chinh la

$\left ( x+1 \right )^{3}+\left ( y+1 \right )^{3}+\left (x+1 \right )+\left ( y+1 \right )=0$

PTDTTHT tim ra x+y=-2

ban tu lam tiep nhe to luoi lam

$6pq+9r>p^{3}$ chung minh the nao a