39-120=91::)

\(\left(\dfrac{4}{5}+\dfrac{1}{2}\right)\cdot\left(\dfrac{3}{15}-\dfrac{8}{13}\right)\)

\(=\dfrac{13}{10}\cdot\left(-\dfrac{27}{65}\right)\)

\(=-\dfrac{27}{50}\)

1/ have
2/ which
3/ though
4/ because
5/ on
6/ of

1/ it => bỏ
2/ have just introduced => has just been introduced

1/ goes
2/ bought
3/ be finished
4/ riding
5/ donate
6/ electricity
7/ disappointed
8/ luckily

A. 25/10=25:5/10:5=5/2
B. 50/20=50:10/20:10=5/2
C. 15/6=15:3/6:3=5/2
D. 20/8=20:4/8:4=5/2 
(: