5.2²+(x+3)=5²

5.4+(x+3)=25

20+(x+3)=25

x+3=25-20

x-3=5

x=5+3

x=8

\(x=8\)

Trả lời

\(5.2^2+\left(x+3\right)=5^2\)

\(5.4+\left(x+3\right)=25\)

\(20+\left(x+3\right)=25\)

          \(x+3=25-20\)

          \(x+3=5\)

          \(x\)        \(=\) \(5-3\)

          \(x\)        \(=\) \(8\)

5x - 5^2 = 10

5x - 25 = 10

5x         = 10 + 25

5x         = 35

  x         = 35 : 5

  x         = 7 

Vậy x = 7 

5x - 5^2 = 10

5x - 25 = 10

5x         = 10 + 25

5x         = 35

  x         = 35 : 5

  x         = 7 

Đây bạn

5x - 5^2 = 10

5x - 25 = 10

5x         = 10 + 25

5x         = 35

  x         = 35 : 5

  x      

  x         = 7 

1)Tính:

a)\(4^2\cdot2=\left(2^2\right)^2\cdot2=2^4\cdot2=2^5=32\)

b)\(36^2:6^2=\left(36:6\right)^2=6^2=48\)

c)\(\left(\frac{2}{5}\right)^{10}:\left(\frac{4}{25}\right)^2=\left(\frac{2}{5}\right)^{10}\cdot\left(\frac{25}{4}\right)^2=\)\(\left(1\right)^{10}\cdot\left(\frac{5}{2}\right)^2=1\cdot\frac{5^2}{2^2}=1\cdot\frac{25}{4}=\frac{25}{4}\)

a

\(4^2.2=16.2=32\)

b\(36^2:6^2=36.36:6.6=36.36:36=36\)

c

3)

a)\(x:\left(-\frac{1}{3}\right)^5=\left(-\frac{1}{3}\right)^3\)

                      \(x=\left(-\frac{1}{3}\right)^3\cdot\left(-\frac{1}{3}\right)^5\)           

                      \(x=\left(-\frac{1}{3}\right)^8\)

b)\(\left(\frac{2}{3}\right)^{16}\cdot x=\left(\frac{2}{3}\right)^{18}\)

                      \(x=\left(\frac{2}{3}\right)^{18}:\left(\frac{2}{3}\right)^{16}\)

                      \(x=\left(\frac{2}{3}\right)^2\)

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

                      \(x=\frac{4}{9}\)

a, 2¹.5².17 = 2.25.17 = 50.17 = 850 

b, 2² + 2³ + 2⁴ = 4 + 8 + 16 = 28

c, 2⁵.3 + 2⁴:8 + 50: 5²

= 32.3 + 16:8 + 50:25

=96 + 2 + 2

= 100

d, 11² - 10² - 3²

= 121 - 100 - 9

= 21 - 9

= 12

e, 1³ + 2³ + 3³ + 4³ + 5³

= ( 1+ 2+3+4+5)²

= 15²

= 225

\(\left(x-3\right)\left(y+5\right)=9\)

Do \(y\in N\Rightarrow\) \(\left(y+5\right)\)\(\ge5\)

\(x\in N\Rightarrow x-3\ge-3\)

\(\Rightarrow\left\{x-3;y+5\right\}=\left\{1;9\right\}\\ \Rightarrow\left\{x;y\right\}=\left\{4;4\right\}\) 

Có: 9 = 1.9 = 9.1 = 3.3

Với (x - 3)(y + 5) = 1.9

\(\text{⇒}\left\{{}\begin{matrix}x-3=1\text{⇒}x=4\\y+5=9\text{⇒}y=4\end{matrix}\right.\)(Thỏa mãn)

Với (x - 3)(y + 5) = 9.1

\(\text{⇒}\left\{{}\begin{matrix}x-3=9\text{⇒}x=12\\x+5=1\text{⇒}x=-4\end{matrix}\right.\)(Ko thỏa mãn)

Với (x - 3)(y + 5) = 3.3

\(\text{⇒}\left\{{}\begin{matrix}x-3=3\text{⇒}x=9\\y+5=3\text{⇒}y=-2\end{matrix}\right.\)(Ko thỏa mãn)

Vậy x=4; y=4

a)4/9 : x/6 = 2/3

           x/6 = 4/9 : 2/3

          x/6  =   2/3 = 4/6

vậy x = 4

b)x/5 x 3/7 = 9/35

   x/5          = 9/35 : 3/7

   x/5          = 3/5

vậy x = 3