(3x - 6) .3 =\(^42\)\(^43\)
a) 5x – 65 = 5.32
b) 200 – (2x + 6) = 43
c) 2(x−51) = 2.23 + 20
d) 135 – 5(x + 4) = 35
e) (2x – 4)(15 – 3x) = 0
f) 2x+1.22014 = 22016
g) 15+(x−1)3=42
h)15 – x = 17+ (−9)
i) | x − 5| = |−7|+(−4)
k) | x − 3| − 12= −9+ | −7|
a) \(5x-65=5.3^2 \\ 5x-65=45\\5x=45+65\\5x=110\\x=22\)
b) \(200-(2x+6)=4^3\\2x+6=200-4^3\\2x+6=136\\2x=130\\x=65\)
c) \(2(x-51)=2.2^3+20\\2(x-51)=16+20\\2(x-51)=36\\x-51=18\\x=51+18=69\)
d) \(135-5(x+4)=35\\5(x+4)=135-45\\5(x-4)=90\\x-4=18\\x=18+4=22\)
e) \((2x-4)(15-3x)=0\\2(x-2).3(5-x)=0\\(x-2)(5-x)=0\\ \left[ \begin{array}{l}x-2=0\\5-x=0\end{array} \right. \\ \left[ \begin{array}{l}x=2\\x=5\end{array} \right.\)
f) \(2^{x+1} . 2^{2014}=2^{2016} \\ (2^{x+1} . 2^{2014}):2^{2014}=2^{2016} :2^{2014} \\ 2^{x=1}=2^{2016-2014} \\2^{x+1}=2^2\\x+1=2\\x=1\)
g) \(15+(x-1)^3=43\\(x-1)^3=15-42\\(x-1)^3=-27\\(x-1)^3=(-3)^3\\x-1=-3\\x=-2\)
h) \(15-x=17+(-9)\\15-x=17-9\\15-x=8\\x=15-8\\x=7\)
i) \(|x-5|=|-7|+|-4|\\|x-5|=7+4\\|x-5|=11\\ \left[ \begin{array}{l}x-5=11\\x-5=-11\end{array} \right. \\ \left[ \begin{array}{l}x=16\\x=-6\end{array} \right.\)
k) \(|x-3|-12=-9+|-7|\\|x-3|-12=-9+7\\|x-3|-12=-2\\|x-3|=10 \\ \left[ \begin{array}{l}x-3=10\\x-3=-10\end{array} \right. \\ \left[ \begin{array}{l}x=13\\x=-7\end{array} \right.\)
Tính giá trị biểu thức:
A = 17 + 3x + 3x2 + 3x3 +... + 3x42 + 3x43 + 3x44 - 3x45 biết x = 4
2 .3 . 12+4 . 6 . 42 +18 . 26. 43
2*3*12+4*6*42+18*26*43
=72+1008+20124
=1080+20124
=21204
3/2+7/6+13/12+21/20+43/42+57/56
Thực hiện các phép tính sau :
1, 37 - 58 + 75 - 58
2, 49 - 54 + 41 - 52 + 59
3, 43 - 27 - 43 - 38 + 27
4, 18 - 43 - ( 18 - 43 ) - 51
5, ( 37 - 54 - 43 ) - ( 37 - 54 + 42 )
6, - ( 39 - 42 + 38 ) - ( 42 - 39 +38 ) + 95
Ai trả lời nhanh mình k cho !!!!! ^-^
Tìm số nguyên x, biết:
a) 4 3 = 2 x − 1 x
b) 2 x − 1 3 = 3 x + 1 4
c) 4 x + 2 = 7 3 x + 1
d) − 3 x + 1 = 4 2 − 2 x
a) Không tồn tại x
b) x = -7
c) x = 2
d) x = 5
3/2+7/6+13/12+21/20+31/30+43/42+57/56+73/72+91/90
Tính nhanh:3/2+7/6+13/12+21/20+31/30+43/42+57/56+73/72
3/2+7/6+13/12+21/20+31/30+43/42+57/56+73/72+91/90
\(=1+1+1+1+1+1+1+1+1+\left(\dfrac{1}{2}+\dfrac{1}{6}+\dfrac{1}{12}+\dfrac{1}{20}+\dfrac{1}{30}+\dfrac{1}{42}+\dfrac{1}{56}+\dfrac{1}{72}+\dfrac{1}{90}\right)\)
\(=9+\left(1-\dfrac{1}{2}+\dfrac{1}{2}-\dfrac{1}{3}+...+\dfrac{1}{9}-\dfrac{1}{10}\right)\)
=9+9/10=99/10