giúp mik vs

7^4 * 7

= 7^(4+1)

= 7^5

= 16807

4x+18:2=13

4x+9=13

4x =4

x =1

4x + 18 : 2 = 13

4x + 9 = 13

4x = 13 - 9

4x = 4

⇒x = 4 : 4

x = 1

Vậy x = 1

\(\frac{5}{2x}-3=\frac{1}{x}\)

\(\frac{5}{2x}-\frac{1}{x}=3\)

\(\frac{5}{2x}-\frac{2}{2x}=3\)

\(\frac{3}{2x}=3\)

\(\frac{1}{2x}=\frac11\)

\(2x=1\)

\(x=\frac12\)

vậy x = \(\frac12\)

5/2.x - 3 = 1/x

⇔ 5x² - 6x = 2

⇔ 5x² - 6x - 2 = 0

Giải phương trình bậc 2:

x = (3 ± √19) / 5

Vậy x = (3 + √19) / 5 hoặc x = (3 - √19) / 5.

\(-\frac57-\left(-\frac{3}{21}\right)\)

\(=-\frac57+\frac{3}{21}\)

\(=-\frac{15+3}{21}\)

\(=-\frac{12}{21}=-\frac47\)

\(\frac{5}{-7}-\frac{-3}{21}\)

\(=\frac{-5}{7}-\frac{-3}{21}\)

\(=\frac{-105}{147}-\frac{-21}{147}\)

\(=\frac{-105-\left(-21\right)}{147}\)

\(=\frac{-105+21}{147}\)

\(=\frac{-84}{147}\)

\(=\frac{-4}{7}\)

\(\left(\frac{x}{7}+0,25\right)=\frac{-1}{28}\)

\(\frac{x}{7}+0,25=\frac{-1}{28}\)

\(\) \(\frac{x}{7}=\frac{-1}{28}-0,25\)

\(\frac{x}{7}=\frac{-2}{7}\)

\(x=2\)

Vậy \(x=2\)

2

3746 x 99 + 3746

= 3746 x (99 + 1)

= 3746 x 100

= 374600

3746 × 99 + 3746 = 3746 × (99 + 1) = 3746 × 100 = 374600

(-3) - (-8) + (-12)

= - 3 + 8 - 12

= 5 - 12

= - 7

x\(^{2015}\) = x\(^{2016}\)

⇒ x\(^{2016}\) - x\(^{2015}\) = 0

⇒ x\(^{2015}\) * (x - 1) = 0

TH1: x\(^{2015}\) = 0

⇒ x\(^{2015}\) = 0\(^{2015}\)

⇒ x = 0

TH2: x - 1 = 0

x = 0 + 1

x = 1

⇒ x ∈ {0; 1}

Vậy x ∈ {0; 1}

1^2015=1^2016

vì đều bằng 1

con dấu

Con dao

\(4^{2x+1}=1024\)

\(\Rightarrow4^{2x+1}=4^5\)

⇒ 2x + 1 = 5

2x = 5 - 1

2x = 4

x = 4 : 2

x = 2

Vậy x = 2

\(4^{2x+1}\) = 1024

(2\(^2\))\(^{2x+1}\) = \(2^{10}\)

\(2^{4x+2}\) = 2\(^{10}\)

4\(x+2\) = 10

4\(x\) = 10 - 2

4\(x\) = 8

\(x\) = 8 : 4

\(x=2\)

Vậy \(x=2\)