Tìm x biết
\(5^{x+2}+5^x=130\)
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Áp dụng tính chất giao hoán, ta có:
68 130 x 9 = 9 x 68 130 = 613 170
5 x 613 170 = 613 170 x 5 = 3 065 850
Áp dụng tính chất kết hợp, ta có:
9 x 68 130 x 5 = 613 170 x 5 = 3 065 850
5 x 9 x 68 130 = 5 x (9 x 68 130) = 5 x 613 170 = 3 065 850
a) 5x - 2 + 5x = 130
<=> 5x : 25 + 5x = 130
<=> 5x ( 1/25 + 1 ) = 130
<=> 5x .26/25 = 130
<=> 5x = 125
<=> x = 3
b) 3x + 2 +3x = 1000 - 190
<=> 3x . 9 + 3x = 810
<=> 3x ( 9 + 1 ) = 810
<=> 3x = 81
<=> x= 4
Ta có:
a) 5x - 2 + 5x = 130
=> 5x . 1/25 + 5x = 130
=> 5x. (1/25 + 1) = 130
=> 5x = 130 : 26/25
=> 5x = 125
=> 5x = 53
=> x = 3
b) 3x + 2 + 3x = 1000 - 190
=> 3x.9 + 3x = 810
=> 3x (9 + 1) = 810
=> 3x.10 = 810
=> 3x = 810/10 = 81
=> 3x = 34
=> x =4
a) \(70-\left(x-3\right)=45\)
\(x-3=70-45\)
\(x-3=25\)
\(x=25+3\)
\(x=28\)
b) \(12+\left(5+x\right)=20\)
\(5+x=20-12\)
\(5+x=8\)
\(x=8-5\)
\(x=3\)
c) \(130-\left(100+x\right)=25\)
\(100+x=130-25\)
\(100+x=105\)
\(x=105-100\)
\(x=5\)
d) \(175+\left(30-x\right)=200\)
\(30-x=200-175\)
\(30-x=25\)
\(x=30-25\)
\(x=5\)
e) \(\left(x+12\right)+22=92\)
\(x+12=92-22\)
\(x+12=70\)
\(x=70-12\)
\(x=58\)
f) \(95-\left(x+2\right)=45\)
\(x+2=95-45\)
\(x+2=50\)
\(x=50-2\)
\(x=48\)
a)
70 - (x - 3) = 45
x - 3 = 70 - 45 = 25
x = 25 + 3 = 28
Vậy x = 28
b)
12 + (5 + x) = 20
5 + x = 20 - 12 = 8
x = 8 - 5 = 3
Vậy x = 3
c)
130 - (100 + x) = 25
100 + x = 130 - 25 = 115
x = 115 - 100 = 15
Vậy x = 15
d)
175 + (30 - x) = 200
30 - x = 200 - 175 = 25
x = 30 - 25 = 5
Vậy x = 5
e)
(x + 12) + 22 = 92
x + 12 = 92 - 22 = 70
x = 70 - 12 = 58
Vậy x = 58
f)
95 - (x + 2) = 45
x + 2 = 95 - 45 = 50
x = 50 - 2 = 48
Vậy x = 48
Ta có : 5x-2 + 5x = 130
=> 5x . \(\frac{1}{25}\)+ 5x = 130
=> 5x . 1.04 = 130
=> 5x = 125 => x=3
a) x – 32 : 16 = 48 ó x – 2 = 48 ó x = 48 + 2 ó x = 50
b) 88 – 3.(7+x) = 64 ó 3.(7+x) = 88 – 64 ó 7 + x = 24:3 ó x = 8 – 7 ó x = 1
c) (5+4x) : 3 – 121 : 11 = 4 ó (5+4x) : 3 – 11 = 4 ó (5+4x) : 3 = 4 + 11 ó 5+4x = 15.3 ó 4x = 45 – 5 ó 4x = 40 ó x = 10
d) 15 – 2(3x+1) = 11.13 – 130 ó 15 – 2(3x+1) = 143 – 130 ó 15 – 2(3x+1) = 13
ó 2(3x+1) = 15 – 13 ó 3x + 1 = 2:2 ó 3x = 1 – 1 ó 3x = 0 ó x = 0
\(\frac{x+10}{30}+\frac{x+14}{43}+\frac{x+5}{95}+\frac{x+130}{5}=0\)
\(\Leftrightarrow\left(\frac{x+10}{30}+3\right)+\left(\frac{x+14}{43}+2\right)+\left(\frac{x+5}{95}+1\right)+\left(\frac{x+130}{5}-6\right)=0\)
\(\Leftrightarrow\frac{x+10+90}{30}+\frac{x+14+86}{43}+\frac{x+5+95}{95}+\frac{x+130-30}{5}=0\)
\(\Leftrightarrow\frac{x+100}{30}+\frac{x+100}{43}+\frac{x+100}{95}+\frac{x+100}{5}=0\)
\(\Leftrightarrow\left(x+100\right)\left(\frac{1}{30}+\frac{1}{43}+\frac{1}{95}+\frac{1}{5}\right)=0\)
Vì \(\frac{1}{30}+\frac{1}{43}+\frac{1}{95}+\frac{1}{5}\ne0\)
=> x + 100 = 0
=> x = -100
5^x . 5^1+ 5^x . 5^3=130/5^x . (5^1+5^3)=130/5^x . 130 =130/5^x=130÷130/5^x=1 vậy x=1 tik nha
\(5^x.\left(5^2+1\right)=130\)
\(5^x.26=130\)
\(5^x=\frac{130}{26}=5\)
\(x=1\)
\(x=1\)