Tom started learning English when he was nine. (SINCE) =>

The last time she had a swim was five years ago. (HAS) =>

I can’t cook as well as my mother does. (BETTER) =>

We were late for school because of the heavy rain. => Because it_________________.

The cake was so hard that I couldn’t eat it. => It was such _____________.

25.C

26.B

27.D

28.B

giải pt:

Cho a,b,c > 0 thỏa mãn \(a\sqrt{\dfrac{b}{c}}+b\sqrt{\dfrac{c}{a}}+c\sqrt{\dfrac{a}{b}}=3\). Chứng minh rằng:
\(N=\dfrac{a^4}{b^2}+\dfrac{b^4}{c^2}+\dfrac{c^4}{a^2}\ge3\)

Cho a,b,c >0 thỏa mãn \(a^4+b^4+c^4=1\) . Tìm GTLN của biểu thức:
\(M=ab^3+bc^3+ca^3\)

1.
A= \(2\sqrt{6}\) + \(6\sqrt{6}\) - \(8\sqrt{6}\)
A= 0
2.
A= \(12\sqrt{3}\) + \(5\sqrt{3}\) - \(12\sqrt{3}\)
A= 0
3.
A= \(3\sqrt{2}\) - \(10\sqrt{2}\) + \(6\sqrt{2}\)
A= -\(\sqrt{2}\)
4.
A= \(3\sqrt{2}\) + \(4\sqrt{2}\) - \(\sqrt{2}\)
A= \(6\sqrt{2}\)
5.
M= \(2\sqrt{5}\) - \(3\sqrt{5}\) + \(\sqrt{5}\)
M= 0
6.
A= 5 - \(3\sqrt{5}\) + \(3\sqrt{5}\)
A= 5

This literally took me a while, pls sub :D
https://www.youtube.com/channel/UC4U1nfBvbS9y_Uu0UjsAyqA/featured