Tìm x:
1) -3.(1-2x) - 4.(1+3x) = -5x + 5
2) 3.(2x - 5) - 6.(1 - 4x) = -3x + 7
3) (1 - 3x) - 2.(3x - 6) = -4x - 5
4) x.(4x - 3) - 2x.(2x - 1) = 5x - 7
5) 3x.(2x - 1) - 6x.(x + 2) = -3x + 4
6) (1 - 2x).3 - 4.(6x - 1) = 7x - 5
7) 6x - 3.(1 - 4x) - 5.(x + 1) = 2x + 7
8) 6.(1 - 3x) - 3.(2x + 5) = -10x + 7
9) 3x.(1 - 2x) + 6x^2 - 7x = 8.(1 - 2x) - 9
10) 2x.(1 + 3x) - 3x.(4 + 2x) = 3x - 4
Chung minh:
a/ \(5^5-5^4+5^3⋮7\)
b/ \(7^6+7^5-7^4⋮11\)
c/ \(3^{x+2}-2^{x+3}+3^x-2^{x+1}⋮10\)
d/ \(3^{x+3}+3^{x+1}+2^{x+3}+2^{x+2}⋮6\)
bài 1;Tìm x thuộc Q biết:
a,(2x-1)\(^8\)= (2x-1)\(^{10}\)
b,(x-1)\(^5\)=(x-1)\(^7\)
a) Tính giá trị biểu thức sau:
\(\dfrac{9^4.8^6}{6^{10}.16^3}\)
b) Tìm x:
1/ \(\left(\dfrac{4}{5}x-1\right).\left(6x+\dfrac{1}{2}\right)=0\)
2/
\(\left(2x+1\right)^2=25\)
3/
x:8,5=0,69:(-1,15)
4/
3(3x+5)-2(6-2x)=10
5/
\(\sqrt{x}=2,5\)
6/
\(3^{X-1}+5.3^{x-1}=162\)
7/
\(\dfrac{X-5}{1}+\dfrac{X-5}{2}+\dfrac{X-5}{3}+\dfrac{X-5}{4}=0\)
\(\left|x-\dfrac{1}{5}\right|-\dfrac{4}{7}=\dfrac{10}{7}\)
tìm x biết
1) \(\dfrac{2}{3}+\dfrac{1}{3}:x=\dfrac{3}{5}\)
2) \(\left(\dfrac{2x}{3}-3\right):\left(-10\right)=\dfrac{2}{5}\)
3) \(2\dfrac{2}{3}:x=2\dfrac{1}{12}:\left(-0,06\right)\)
4) \(\dfrac{3}{7}+\dfrac{1}{7}:x=\dfrac{3}{14}\)
5) \(-\dfrac{3}{5}.x-\dfrac{1}{2}=-\dfrac{1}{7}\)
6) \(\dfrac{1}{5}+2x=-2\dfrac{1}{4}\)
7)\(-\dfrac{1}{2}:x=\dfrac{3}{8}:\dfrac{9}{16}\)
8)\(\dfrac{2}{3}:x=2\dfrac{1}{2}:\left(-0,3\right)\)
9) \(\dfrac{x}{3}=\dfrac{-2}{1,5}\)
tìm x,y,z biết:
câu 3:x/y=5/9 và x-y=-40
câu b: x/2=y/3 và 5.x-2.y=28
câu c: x/5=y/7=z/10 và x+y-z=20
câu d: x/3=y/4=z/5 và 3.x-2.y+2.z=121
câu e: x/4=y/2 và y/3=z/5 và x+y-z=20
\(\dfrac{2}{5}x=\dfrac{4}{7}y=\dfrac{5}{6}z\) và x+y+z=545
\(\dfrac{x}{19}=\dfrac{y}{12}\) và x-2y=10
Bài 1 Tính
a) 45^10x5^10/75^10
b ) 2^15.9^4/6^3.8^3
c ) (0.8)^5/(0.4)^6
d ) 8^10+4^10/8^4+4^11
Bài 2 Tìm x
a ) (5x-1).(2x-1/3)=0
b) \(^{2^{x-1}}\)= 16
c ) 3^4<1/9.27^x<3^10
