\(\frac{3}{4}+\frac{1}{4}\)

=\(\frac{3+1}{4}\)

=\(\frac{4}{4}\)

=1

t tôi nhá bn

x=100 ung ho nhe

tập hợp A các số tự nhiên nhỏ hơn 100

C1 : A = { 0 ; 1 ; 2 ; 3 ; 4 ; 5 ; ... ; 100 }

C2  : A = { x\(\in\)N | x < 100 }

Rewrite the second sentence so that it has a similar meaning to the first one.
1/ It is interesting to learn English.
→ Learning English is interesting.
2/ He failed his exam because he was lazy.
→Because of his laziness he failed his exam.
3/ He uses all his free time to look after his garden.
→He spends all his time looking after his garden.
4/ Nobody cleaned the floor yesterday.
→The floor wasn't cleaned yesterday.
5/ It is two months since I saw her.
→I haven't seen her for two months.