\(5^x+5^{x+1}+5^{x+2}+5^{x+3}=1+2+3+...+87+88-4^2\)

=>\(5^x+5^x\cdot5+5^x\cdot25+5^x\cdot125=88\cdot\dfrac{\left(88+1\right)}{2}-16\)

=>\(156\cdot5^x=44\cdot89-16=3900\)

=>\(5^x=\dfrac{3900}{156}=25\)

=>x=2

Lời giải:

$5^x+5^{x+1}+5^{x+2}+5^{x+3}=1+2+3+...+87+88-4^2$

$5^x(1+5+5^2+5^3)=88.89:2-16$

$5^x.156=3900$

$5^x=3900:156=25=5^2$

$\Rightarrow x=2$

1/2.2x+4.2x=9.2x

2x.(1/2+4)=9.2x

2x.9/2=9.2x

2x:2x=9:9/2

x=2

vậy x=2

5x+5x+1+5x+2=31

5x + 5x + 5x = 31 - 2 - 1 

15x = 28

x= 28/15

a, 42x - 6 = 1

=> 42 x = 7 

=> x = 6

b, 5x + 5x + 1 +5x + 2 = 775

=> 15 x + 3 = 775

=> 15 x = 772

=> x = 772/ 15

a,= > = 6

b,= > x = 772 / 15

⇔2^x=2⁸:2

⇔2^x=2⁷

⇒x=7

Cảm ơn 

2^7

2^x+1 = 2⁸

=> x + 1 = 8

=> x = 8 - 1 = 7

2⁵ˣ⁺¹ - 2⁵ˣ = 32

2⁵ˣ.(2 - 1) = 2⁵

2⁵ˣ = 2⁵

5x = 5

x = 5 : 5

x = 1

\(2^{5x+1}-2^{5x}=32\)

\(\Rightarrow2^{5x+1}-2^{5x}=2^5\)

\(\Rightarrow2^{5x}\cdot2-2^{5x}\cdot1=2^5\)

\(\Rightarrow2^{5x}\cdot\left(2-1\right)=2^5\)

\(\Rightarrow2^{5x}\cdot1=2^5\)

\(\Rightarrow2^{5x}=2^5\)

\(\Rightarrow5x=5\)

\(\Rightarrow x=\dfrac{5}{5}\)

\(\Rightarrow x=1\)

\(\left(1-3x\right)+\left(x-3\right)=\left(5x-1\right)-\left(5x+3\right)\)

\(\Rightarrow1-3x+x-3=5x-1-5x-3\)

\(\Rightarrow\left(1-3\right)-\left(3x-x\right)=\left(5x-5x\right)-\left(1+3\right)\)

\(\Rightarrow-2-2x=-4\)

\(\Rightarrow2x=-2+4\)

\(\Rightarrow2x=2\)

\(\Rightarrow x=1\)

Vậy \(x=1\)