\(\frac{x}{27}-\frac{2}{9}=\frac{6}{18}\)

\(\frac{x}{27}=\frac{6}{18}-\frac{2}{9}\)

\(\frac{x}{27}=\frac{3}{9}-\frac{2}{9}\)

\(\frac{x}{27}=\frac{1}{9}\)

\(\frac{x}{27}=\frac{3}{27}\)

\(x=3\)

Ấy nhầm, làm lại nha:

\(\frac{x}{27}-\frac{2}{9}=\frac{6}{18}\)

\(\frac{x}{27}=\frac{6}{18}+\frac{2}{9}\)

\(\frac{x}{27}=\frac{3}{9}+\frac{2}{9}\)

\(\frac{x}{27}=\frac{5}{9}\)

\(\frac{x}{27}=\frac{15}{27}\)

\(x=15\)

\(\frac{15}{26}+\frac{x}{13}=\frac{46}{52}\)

\(\frac{x}{13}=\frac{46}{52}-\frac{15}{26}\)

\(\frac{x}{13}=\frac{23}{26}-\frac{15}{26}\)

\(\frac{x}{13}=\frac{8}{26}\)

\(\frac{x}{13}=\frac{4}{13}\)

\(x=4\)

1. so cac so hang trong day cach deu la:

 \(\left(100-10\right)\div2+1=46\)(so hang)

tong cac so hang trong day cach deu la:

  \(\left(100+10\right)\times46\div2=2530\)

                               dap so:2530

minh chi lam dc bai 1 thoi sorry ban

Bài 1 : 

10+12+14+...+98+100

Số số hạng của dãy trên là : (100-10):2+1=46 ( số )

Tổng  của dãy trên là : (100+10)×46:2=2530

=> 10+12+14+...+98+100=2530

Bài 2 :         

2^x+1=129

2^x=129-1

2^x=128

2^x=2^7

=> x=7

Vậy x =7

153-x^3=10

x^3=153-10

x^3=143

Câu này sai đề phải không bạn ?

​

a: \(A\left(109\right)=x^{99}-x^{98}\cdot x+x^{98}-x^{97}\cdot x+...+x-x\)

\(=x^{99}-x^{99}+x^{98}-x^{98}+...+0\)

=0

b: x=9 nên x+1=10

\(B\left(x\right)=x^{49}-x^{48}\left(x+1\right)+x^{47}\left(x+1\right)-...+x\left(x+1\right)-1\)

\(=x^{49}-x^{49}-x^{48}+x^{48}+...+x^2+x-1\)

=x-1=8

c: x=999 nên x+1=1000

\(C\left(x\right)=x^{999}-x^{998}\left(x+1\right)+x^{997}\left(x+1\right)-...+x\left(x+1\right)-1\)

\(=x^{999}-x^{999}-x^{998}+x^{998}+...+x^2+x-1\)

=x-1=998

\(\frac{x}{13}:\frac{15}{16}=\frac{46}{52}\)

\(\Rightarrow\frac{x}{13}=\frac{46}{52}\cdot\frac{15}{16}=\frac{23}{26}\cdot\frac{15}{16}\)

\(\Rightarrow\frac{x}{13}=\frac{345}{416}\)

\(\Rightarrow x=\frac{345}{416}\cdot13=\frac{345}{32}\)

Vậy \(x=\frac{345}{32}\)

K MK ĐI. ~ HỌC TỐT NHA ~

\(\frac{x}{13}:\frac{15}{16}=\frac{46}{52}\)

\(\Rightarrow\frac{x}{13}:\frac{15}{16}=\frac{23}{26}\)

\(\Rightarrow\frac{x}{13}=\frac{23}{26}\times\frac{15}{16}\)

\(\Rightarrow\frac{x}{13}=\frac{345}{416}\)

\(\Leftrightarrow416\times x=13\times345\)

\(\Rightarrow416\times x=4485\)

\(\Rightarrow x=4485:416\)

\(\Rightarrow x=\frac{345}{32}\)

\(\frac{x}{13}\div\frac{15}{16}=\frac{46}{52}\)

\(\Rightarrow\frac{x}{13}\div\frac{15}{16}=\frac{23}{26}\)

\(\Rightarrow x\div13=\frac{345}{416}\)

\(\Rightarrow x=\frac{345}{52}\)

~Study well~

#Thạc_Trân

a)Ta có: 109=x =>x⁹⁹-109x⁹⁸+109x⁹⁷-...+x-109

A(109)=(x⁹⁹-xx⁹⁸)+(xx⁹⁷-xx⁹⁶ )+...+(x-x)=(x⁹⁹-x⁹⁹)+(x⁹⁷-x⁹⁷)+...+0=0

Vậy A(109)=0

b) Ta có :x=9 => x⁴⁹-(x+1)x⁴⁸+(x+1)x⁴⁷+...+(x+1)x-1

B(9)=x⁴⁹-x⁴⁹-x⁴⁸+x⁴⁸+x⁴⁷-...+x²+x-1=x-1=9-1=8

Vậy :B(9)=8

c) Làm tương tự câu b => C(999)=998

Nhầm, làm lại nhé!

\(\frac{x}{13}+\frac{15}{26}=\frac{46}{52}\)

\(\frac{x}{13}+\frac{15}{26}=\frac{23}{26}\)

\(\frac{x}{13}=\frac{23}{26}-\frac{15}{26}\)

\(\frac{x}{13}=\frac{23}{26}-\frac{15}{26}\)

\(\frac{x}{13}=\frac{4}{13}\)

\(\Rightarrow x=\frac{13.4}{13}=4\)

Vậy \(x=4\)

X= 4 phải ko mọi người

ko phải

Vậy = bao nhiêu

\(\frac{15}{26}+\frac{x}{16}=\frac{46}{52}\)

\(\frac{x}{16}=\frac{46}{52}-\frac{15}{26}\)

\(\frac{x}{16}=\frac{1}{4}\)

4 : 1 = 4

Suy ra x = 4

HkT~

#Wind

x = 16

HT