1+1=?
2+2=?
3+3x3-3-3^3:3-(3+3).3-3:(3+3.3)=?
3/4+2/3+3/4+1/3+1/3.3/1
Tìm số thực xx, biết:
a) 3√x<2x3<2 :
b) 3√2x−1>−3:2x−13>−3:
c) 3√2−3x≤1:2−3x3≤1:
d) 3√3−4x≥53−4x3≥5.
1+1-1x2:1=?
2+2-2x2:2=?
3+3-3x3:3=?
Bằng 0 hết nha bạn
=1 ; 2 ; 3 lần lượt các câu
1+1-1x2:1=2-2=0
2+2-2x2:2=4-2=2
3+3-3x3:3=9-3=6
1 +1+1+1+1+1+1+1
2+2+2+2+2+2+2+2+2
3 +3x3+3+3x3 x3 +1 =
1x8=8
2x9=18
3x1+3x3+3x1+3x3+1
= 3x( 1+3+1+3)+1
=3x8+1
=24+1=25
1 +1+1+1+1+1+1+1=8
2+2+2+2+2+2+2+2+2=18
3 +3x3+3+3x3 x3 +1 =43
Bộ bốn nào dưới đây có thể lập thành tỉ lệ thức :
a) 46 1/2 ;60 3/5 ;77 1/2 ; 101
b)-1/8 ;5;6;-4,5 và 31,5
c) (1+2+3)^2 ; (1+2+3)^3 ; 1^3+2^3+3^3 và 1^3.2^3.3^3
help me
\(3^{6n-1}=3^{6n-6}.3^5=3^{6\left(n-1\right)}.3^5=3^{3\left(2n-2\right)}.3^5=27^{2n-2}.3^3.3^2\)\(\equiv\left(-1\right)^{2n-2}.6.2=12\equiv5\left(mod7\right)\)
(x+1)^3 =2^3.3+3
5+2.3^x+2=23
(2x-1)^5=32
49.7^x+1=49^8
3^x+3-3^x=234
\(\left(x+1\right)^3=2^3.3+3\)
\(\Rightarrow\left(x+1\right)^3=24+3=27=3^3\)
\(\Rightarrow x+1=3\Rightarrow x=2\)
\(5+2.3^x+2=23\)
\(\Rightarrow7+2.3^x=23\)
\(\Rightarrow2.3^x=23-7=16\)
\(\Rightarrow3^x=8.\)
Mà số 3 lũy thừa mấy cũng không thể bằng 8 => x không thỏa mãn.
Rút gọn các biểu thức sau:
a) 4x2(5x2 + 3) – 6x(3x3 – 2x + 1) – 5x3 (2x – 1)
b) \(\dfrac{3}{2}x\left( {{x^2} - \dfrac{2}{3}x + 2} \right) - \dfrac{5}{3}{x^2}(x + \dfrac{6}{5})\)
a) 4x2(5x2 + 3) – 6x(3x3 – 2x + 1) – 5x3 (2x – 1)
= 4x2 . 5x2 + 4x2 . 3 – [6x . 3x3 + 6x . (-2x) + 6x . 1] – [5x3 . 2x + 5x3 . (-1)]
= 20x4 + 12x2 – (18x4 – 12x2 + 6x) – (10x4 – 5x3)
= 20x4 + 12x2 - 18x4 + 12x2 - 6x - 10x4 + 5x3
= (20x4 – 18x4 - 10x4 ) + 5x3 + (12x2 + 12x2 ) – 6x
= -8x4 + 5x3 + 24x2 – 6x
\(\begin{array}{l}b)\dfrac{3}{2}x\left( {{x^2} - \dfrac{2}{3}x + 2} \right) - \dfrac{5}{3}{x^2}(x + \dfrac{6}{5})\\ = \dfrac{3}{2}x.{x^2} + \dfrac{3}{2}x.( - \dfrac{2}{3}x) + \dfrac{3}{2}x.2 - (\dfrac{5}{3}{x^2}.x + \dfrac{5}{3}{x^2}.\dfrac{6}{5})\\ = \dfrac{3}{2}{x^3} - {x^2} + 3x - (\dfrac{5}{3}{x^3} + 2{x^2})\\ = \dfrac{3}{2}{x^3} - {x^2} + 3x - \dfrac{5}{3}{x^3} - 2{x^2}\\ = (\dfrac{3}{2}{x^3} - \dfrac{5}{3}{x^3}) + ( - {x^2} - 2{x^2}) + 3x\\ = \dfrac{{ - 1}}{6}{x^3} - 3{x^2} + 3x\end{array}\)
Tính nhanh
B=1*2+2*3.......+100*101
C=1*3+3*5+......+99*101
D=1!+2.2!+3.3!+.....+10*10!