5.3x = 8.310 - 3.310 

<=> 5.3x = ( 8-3 ) . 310

<=> 5.3x = 5 .310 

<=>    x = 10 

5.3^x = 8.3¹⁰ - 3.3¹⁰ 

<=> 5.3^x = ( 8-3 ) . 3¹⁰

<=> 5.3^x = 5 .3¹⁰ 

<=>    x = 10 

>< 

\(5.3^x=8.3^{10}-3.3^{10}\)

\(\Rightarrow5.3^x=\left(8-3\right).3^{10}\)

\(\Rightarrow5.3^x=5.3^{10}\)

\(\Rightarrow x=10\)

I have a crazy idea chơi bửn thế. Sao lại chép đáp án của Nguyen Thuy Trinh

Câu b

\(5\cdot3^x=8\cdot3^9+7\cdot27^3\)

\(\Leftrightarrow5\cdot3^x=8\cdot3^9+7\cdot\left(3^3\right)^3\)

\(\Leftrightarrow5\cdot3^x=8\cdot3^9+7\cdot^9\)

\(\Leftrightarrow5\cdot3^x=15\cdot3^9\)

\(\Leftrightarrow3^x=3\cdot3^9=3^{10}\)

Vậy \(x=10\)

#kido

a. 37-7.(x+1)=40-8.3

37 - 7(x+1) = 16 

7(x+1) = 21

x+1 = 3

x=2

b. (x+5).3=11=10+(3+4).4

(sao có 2 dấu bằng, dấu nào là dấu cộng do viết nhầm ???)

c. 25-5.3+4.10=100-5.x

50 = 100 - 5x 

5x = 50

x=10

d. 36+2.(x-7)=12+8.(3+5)-36

36 + 2(x-7) = 40

2(x-7) = 4

x-7 =2

x=9

e. 3.(x+7)-9=11.5-5-8

3(x+7) - 9 = 42 

3(x+7) = 51

x+7 = 17 

x=10

1/ ta co

vi x \(\in Z\Rightarrow x\in\left\{-9;-8;..;9;10\right\}\)

Tong cac so x thoa man la

-9+(-8)+(-7)+....+9+10

=(-9+9)+(-8+8)+...+(-1+1)+0

=0+0+0+..+0+0

=0

vay tong cac so ma x thoa man la 0

2/ ta co

vi x \(\in Z\Rightarrow x\in\left\{-8;-7;..;5;6;7\right\}\)

Tong cac so ma x thoa man la

-8+(-7)+(-6)+...+6+7

=-8+0+(-7+7)+(-6+6)+(-5+5)+...+(-1+1)

=-8+0+0+0+...+0

=-8

vay tong cac gia tri ma x thoa man la -8

3/ ta co

vi x \(\in Z\Rightarrow x\in\left\{-22;-21;...;22;23\right\}\)

Tong cac gia tri ma x thoa man la

(-22)+(-21)+....+22+23

=23+0+(-21+21)+(-22+22)+...+(-1+1)

=23+0+0+0+...+0

=23

vay tong cac gia tri ma x thoa man la 23

4/ ta co :

vi |x|\(\le2\Rightarrow\left|x\right|\in\left\{1;2\right\}hay.x\in\left\{2;1;-1;-2\right\}\)

Tong cac gia tri ma x thoa man la :

2+1+(-1)+(-2)

=3+(-3)

=0

vay tong cac gia tri ma x thoa man la 0

5/ ta co

│-x│< 13 nen |x| \(\in\left\{12;11;10;..;2;1;0;-1;-2;...\right\}\)

hay x \(\in\left\{12;11;10;9;...;1;0;-12;-13;...;-1\right\}\)

Tong cac so ma x thoa man la

12+13+14+15+....+1+0+(-1)+(-2)+....+(-12)

=(-12+12)+(-13+13)+...+(-1+1)+0

=0+0+0+0+...+0+0

=0

Vay tong cac gia tri ma x thoa man la 0

7) \(\dfrac{-5}{17}+\dfrac{3}{17}\le\dfrac{x}{17}\le\dfrac{13}{17}+\dfrac{-11}{17}\)

\(\Rightarrow\dfrac{-2}{17}\le\dfrac{x}{17}\le\dfrac{2}{17}\)

\(\Rightarrow-2\le x\le2\)

\(\Rightarrow x\in\left\{-2;-1;0;1;2\right\}\)

8) \(\dfrac{2}{3}\left(\dfrac{1}{2}+\dfrac{3}{4}-\dfrac{1}{3}\right)\le\dfrac{x}{18}\le\dfrac{7}{3}\left(\dfrac{1}{2}-\dfrac{1}{6}\right)\)

\(\Rightarrow\dfrac{2}{3}\left(\dfrac{6}{12}+\dfrac{9}{12}-\dfrac{4}{12}\right)\le\dfrac{x}{18}\le\dfrac{7}{3}\left(\dfrac{6}{12}-\dfrac{2}{12}\right)\)

\(\Rightarrow\dfrac{2}{3}\cdot\dfrac{11}{12}\le\dfrac{x}{18}\le\dfrac{7}{3}\cdot\dfrac{4}{12}\)

\(\Rightarrow\dfrac{22}{36}\le\dfrac{x}{18}\le\dfrac{28}{36}\)

\(\Rightarrow\dfrac{11}{18}\le\dfrac{x}{18}\le\dfrac{14}{18}\)

\(\Rightarrow x\in\left\{11;12;13;14\right\}\)

8) \(\dfrac{2}{3}\left(\dfrac{1}{2}+\dfrac{3}{4}-\dfrac{1}{3}\right)\le\dfrac{x}{18}\le\dfrac{7}{3}\left(\dfrac{1}{2}-\dfrac{1}{6}\right)\\ \dfrac{2}{3}\left(\dfrac{6}{12}+\dfrac{9}{12}-\dfrac{4}{12}\right)\le\dfrac{x}{18}\le\dfrac{7}{3}\left(\dfrac{3}{6}-\dfrac{1}{6}\right)\\ \dfrac{2}{3}.\dfrac{11}{12}\le\dfrac{x}{18}\le\dfrac{7}{3}.\dfrac{2}{6}\\ \dfrac{11}{18}\le\dfrac{x}{18}\le\dfrac{14}{18}\\ \Rightarrow11\le x\le14\\ \Rightarrow x\in\left\{11;12;13;14\right\}\)

7) \(\dfrac{-5}{17}+\dfrac{3}{17}\le\dfrac{x}{17}\le\dfrac{13}{17}+\dfrac{-11}{17}\\ \dfrac{-2}{17}\le\dfrac{x}{17}\le\dfrac{2}{17}\\ \Rightarrow-2\le x\le2\\ \Rightarrow x\in\left\{-2;-1;0;1;2\right\}\)

x + 25| + |−y + 5| = 0

⇒ |x + 25| = 0 và |−y + 5| = 0

|x + 25| = 0

⇒ x + 25 = 0

⇒ x = −25

|−y + 5| = 0

⇒ −y + 5 = 0

⇒ −y = −5

⇒ y = 5

Vậy cặp số  ( x,y) là (−25; 5)

Ai giải hộ e với e phải đi học

a. 8 + (x - 9) = 125 - 64

8 + (x - 9) = 61

x - 9 = 53

x = 62

b. 5 x (X + 7) - 10 = 8 x 5

5 x (X + 7) - 10 = 40

5 x (X + 7) = 50

X + 7 = 10

X = 3

\(\dfrac{-8}{13}+\dfrac{-7}{17}+\dfrac{21}{13}\le x\le\dfrac{-9}{14}+3+\dfrac{5}{-14}\)

=> \(\dfrac{10}{17}\le x\le2\)

=> \(\dfrac{10}{17}\le\dfrac{17x}{17}\le\dfrac{34}{17}\)

=> 10 \(\le17x\le34\)
=> x = 1; 2 (thỏa mãn)
@Khánh Linh