Question

cho biet x va y la hai dai luong ti le thuan,biet khi x=-5 thi y=20.Hay tim he so ti le cua y doi voi x

Answer 1

Gọi hstl là k

\(\Leftrightarrow k=\dfrac{y}{x}=\dfrac{20}{4}=5\)

Answer 2

cho tam giac DEF co DE =DF, phan giac cua goc D cat canh EF tai I 

a,chug minh _{^{tren \(\Delta DIE=DIF\)}}

b. tren canh de lay diem M ,tren tia doi cua tia FD lay diem N sao cho EM =FN .ke MH vuong goc voi EF tai H ,NK vuong goc voi EF tai K. CMR:MH=NK