1. Tìm x \(\in\) Q, biết
a) (x-\(\dfrac{1}{3}\))\(^2\) = 0
b) (x+\(\dfrac{1}{2}\))\(^2\) = \(\dfrac{1}{16}\)
c) (2x-1)\(^3\) = 8
Giúp mk vs
a) (x - \(\dfrac{1}{3}\))2=0
=> x- \(\dfrac{1}{3}\)=0
x=\(\dfrac{1}{3}\)
b) (x + \(\dfrac{1}{2}\))2=\(\dfrac{1}{16}\)
=> (x+\(\dfrac{1}{2}\)) 2= (\(\dfrac{1}{4}\))2=(\(\dfrac{-1}{4}\))2
TH1: x+ \(\dfrac{1}{2}\)=\(\dfrac{1}{4}\)
x= \(\dfrac{-1}{4}\)
TH2 : x + \(\dfrac{1}{2}\)= \(\dfrac{-1}{4}\)
x = \(\dfrac{-3}{4}\)
Vậy x = \(\dfrac{-1}{4}\); \(\dfrac{-3}{4}\)
c) (2x-1)3 =8
=> 2x - 1 = 2
2x = 3
x = \(\dfrac{3}{2}\)
2) Tìm x \in∈ N*
a)27<3x<3.81
b)415.915<2x.3x<1816.216
c)(2x-1)6=(2x-1)8
giúp mình nha, mình đang cần gấp
1)Tìm x biết:
A)\(\left(\dfrac{2}{5}-3x\right)^2=\dfrac{9}{25}\)
B)\(\left(\dfrac{2}{3}x-\dfrac{1}{3}\right)^5=\dfrac{1}{243}\)
2)So sánh:
A)\(5^{222}và\)\(2^{555}\)
B)\(3^{48}và4^{36}\)
Cho biết:
13+23+33+...+103=3025
Tính: a)A=23+43+63+...+203
b) B= 0,53+13+1,53+...+53
Tim tat ca cac so tu nhien n sao cho
a,23.32\(\ge\)2n>16
b,25<5n<625
Tính giá trị biểu thức
\(A=\left(\dfrac{ab}{2}-\dfrac{6ab}{7}\right):\dfrac{5b^2}{14}biết;a=\dfrac{2007}{2010},b=\dfrac{2015}{2016}\)
rút gọn A= 1+22+24+...+250
Chứng minh 810-89-88 chia hết cho 11
Tìm x:
(2-1)x+2=(x-1)x+4
Giải giúp mik vs
Tính:
\(\left(\dfrac{1}{10}\right)^{10}.\left(\dfrac{1}{2}\right)^{50}\)
tìm x biết
a) \(\dfrac{2}{5}-\left(\dfrac{1}{10}-x\right)=\left(\dfrac{-2}{5}-\dfrac{1}{2}\right)^2\)
b) \(\dfrac{2}{5}-\dfrac{3}{5}\left(x-2\right)=\left(\dfrac{-1}{2}\right)^3-\left(\dfrac{3}{4}\right)^3.\left(-2\right)^2\)
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