D.{\(-\dfrac{8}{5}\)}

D.5

a)4P + 5O₂  t^o\(\rightarrow\) 2P₂O₅

P₂O₅  là oxit axit đọc là điphotpho pentaoxit

b)2K + 2H₂O \(\rightarrow\) 2KOH + H₂

KOH là bazơ đọc là Kali hiđroxit

c)SO₃ + H₂O \(\rightarrow\)H₂SO₄

H₂SO₄ là axit đọc là axit sunfuric

d) Zn + HCl \(\rightarrow\)ZnCl₂ + H₂

ZnCl₂  là muối đọc là Kẽm clorua

You are on a vacation in Australia, complete the postcard.

Dear Jun,

a) I / have/ wonderful trip / Australia/ now /

..........................................

b) Australian people / helpful / friendly/ weather / warm / sunny/ during / trip/

............................................

c) Yesterday / I / meet / my friend Jason / Sydney / he/ take/ me see many beautiful spots/

..........................................

Right now we are visiting Sydney Opera House. I'm buying you a model of Sydney Opera House and the kids some stuffed koala bears

Your friends,

d) .............

Diện tích hình thang là

S = \(\dfrac{1}{2}.\left(5+3\right).4\)= 16(cm²)

Đáp số : 16 cm²

D.S[i]