\(\frac{x-15}{100}+\frac{x-10}{105}+\frac{x-5}{110}=\frac{x-100}{15}+\frac{x-105}{10}+\frac{x-110}{5}\)

=> \(\left(\frac{x-15}{100}-1\right)+\left(\frac{x-10}{105}-1\right)+\left(\frac{x-5}{110}-1\right)=\left(\frac{x-100}{15}-1\right)+\)

\(\left(\frac{x-105}{10}-1\right)+\left(\frac{x-110}{5}-1\right)\)

=> \(\frac{x-115}{100}+\frac{x-115}{105}+\frac{x-115}{110}=\frac{x-115}{15}+\frac{x-115}{10}+\frac{x-115}{5}\)

=> \(\left(x-115\right)\left(\frac{1}{100}+\frac{1}{105}+\frac{1}{110}-\frac{1}{15}-\frac{1}{10}-\frac{1}{5}\right)=0\)

=> x - 115 = 0 (Vì \(\frac{1}{100}+\frac{1}{105}+\frac{1}{110}-\frac{1}{15}-\frac{1}{10}-\frac{1}{5}\ne0\)

=> x = 115

Đặt \(V=\frac{a^2}{b^2}+\frac{b^2}{a^2}\ge\frac{a}{b}+\frac{b}{a}\)\(=\left(\frac{a^2}{b^2}+\frac{b^2}{a^2}\right)-\left(\frac{a}{b}+\frac{b}{a}\right)=\left(\frac{a^2}{b^2}+\frac{b^2}{a^2}\right)-2\left(\frac{a}{b}+\frac{b}{a}\right)+\left(\frac{a}{b}+\frac{b}{a}\right)\)

Vì a,b dương \(\Rightarrow A\ge\left(\frac{a^2}{b^2}+\frac{b^2}{a^2}\right)-2\left(\frac{a}{b}+\frac{b}{a}\right)+2=\left(\frac{a}{b}-1\right)^2+\left(\frac{b}{a}-1\right)^2\ge0\)

Circle the words (A,B,C or D) whose underlined part ids pronounced differently.

1, A.physical     B. visual            C. music             D. because

2, A.pollution     B. earplug         C. dump.            D. dust

3, A.thermal      B . thankful        C. there              D through

Circle the words (A,B,C or D) whose main stress is diferent from the others.

4, A.classic           B. nature      C. degree        D. debris

5, A.examinee      B. electronic       C.scientific     D. preparation

1) 1.B 2.A 3.C 

2)4.C 5.A

Vì A(III) và \(PO_x\left(II\right)\)

Vậy CT của hợp chất có dạng là \(A_2\left(PO_x\right)_3\)

Mà \(PTK_{HC}=10,5.PTK_{N_2}=10,5.28=294đvC\)

\(\rightarrow2PTK_A+31.3+3X.16=294\)

\(\rightarrow2PTK_A=201-48x\)

Mặt khác trong 1mol hợp chất \(n_O=\frac{294.48,97959\%}{16}\approx9mol\)

\(\rightarrow3x=9\)

\(\rightarrow x=3\)

\(\rightarrow2PTK_A=201-48.3=57\)

\(\rightarrow PTK_A=28,5\) (Loại)

Vậy không có hợp chất A và CTHC thoả mãn.