a. 2^x+3+2x=144
b. 3^x+25=26.2^2+2.3^0
tìm x biết
a. 2^x+3+2x=144
b. 3^x+25=26.2^2+2.3^0
3^x +25 = 26.2^2+2.3^0
3x+25=26.20+2.30
3x+25=26.1+2.1
3x+25=28
3x=3
x=1
3x+25=26.20+2.30
3x+25=26.1+2.1
3x+25=28
3x=3
x=1
3^x +25 = 26.2^2+2.3^0
<=> 3^x+25= 26.4+2.1
<=> 3^x+25= 106
<=> 3^x= 106-25
<=> 3^x= 81
Mà 81= 3^4
=> x=4
3^x +25 = 26.2^2+2.3^0
\(3^x+25=26.2^2+2.3^0\)
\(3^x+25=104+2\)
\(3^x+25=106\)
\(3^x=81=3^4\)
Vậy x=4
3^x+25=26 . 2^2 + 2. 3^0
3^x+25=104 +2
3^x+25=106
3^x=106+25
3^x=81=3^4
=> x=4
3
x
+25=26.2
2
+2.3
0
3
𝑥
+
25
=
104
+
2
3
x
+25=104+2
3
𝑥
+
25
=
106
3
x
+25=106
3
𝑥
=
81
=
3
4
3
x
=81=3
4
Vậy x=4
a) (7x-11)^3=2^5.5^2+200
b) 3^x+25=26.2^2+2.3^0
Tìm x thuộc N biết
3^3+25=26.2^2+2.3^6
(x-2)^20-(x-2)^18=0
3^x +25 = 26.2^0+2.3^0
3^x +25 = 26.2^0+2.3^0
\(3^x+25=26.2^0+2.3^0\)
\(\Rightarrow3^x+25=26+2\Rightarrow3^x+25=28\)
\(\Rightarrow3^x=3\Rightarrow x=1\)
3x+25=26.20+2.30
3x+25=26.1+2.1
3x+25=28
3x=3
x=1
Tìm x thuộc N biết
33+25=26.22+2.36
(x-2)20-(x-2)18=0
(x-2)^20-(x-2)^18=0
(x-2)^18[(x-2)^2-1]=0
suy ra (x-2)^18=0;(x-2)^2-1=0
x-2=0 ;(x-2)^2=1 ;(x-2)^2=-1
x=2 ;x-2=1 ;x-2=-1
x=3 x=1