( 2.x - 15 ) mũ 3 = ( 2.x - 15 ) mũ 3
Tìm x , y biết
a ) x mũ 2 = x mũ 5
b ) ( 3x - 12 )mũ 15 = ( x - 17)mũ 15
c ) ( 4x - 16 )mũ 15 - ( x - 2 )mũ 15 = 0
d ) ( x - 3 )mũ 11 = ( 2x - 6 )mũ 11
bạn có thể check lại đề bài câu a được không ạ
2 mũ 4 . x - 3 mũ 2 . x = 144 - 164 : 41
165 - ( 35 : x + 3 ) . 15 = 15
2 mũ x + 1 = 4 . 128
5 mũ 3 x + 2 = 25 mũ x + 3
( x - 1 ) mũ 2 = ( x - 1 ) mũ 10
a) \(2^{4x}-3^{2x}=144-164:41\)
\(\Leftrightarrow16^x-9^x=144-4\)
\(\Leftrightarrow\) ......
bjan tự tính tiếp đc òi
Tính :
a) 145 - 5 x [( 13 - 5 )mũ 2 - 2 mũ 2 : 15 ]
b) ( 4 + 3 mũ 2 ) mũ 2 - 3 x [ 15 - ( 5 mũ 2 - 3 mũ 2 ) mũ 2 ]
a)145-5[8^2-4:15]=145-5[64-4/15]=145-5.956/15=145-956/3=-521/3
b)13^2-3[15-16^2]=13^2-3.-241=169--723=892
giải chi tiết hộ mình ạ
bài 1; sắp sếp các đa thức sau theo luỹ thừa giảm dần của biến và thực hiện phép tính chia
a, ( 6x - 5x mũ 2 - 15 + 2x mũ 3 ) : ( 2x - 5 )
b, ( x mũ 3 + 2x mũ 4 - 5x mũ 2 - 3 - 3x ) : ( x mũ 2 - 3 )
c, ( 5x mũ 2 + 15 - 3x mũ 2 - 9x ) : ( 5 - 3x )
d, ( x mũ 3 + x mũ 5 + x mũ 2 + 1 ) : ( x mũ 3 + 1 )
e, ( 3 - 2x + 2x mũ 3 + 5x mũ 2 ) : ( 2x mũ 2 - x + 1 )
=0 bạn nha
tìm x, biết:
a) (2x-1) mũ 20= (2x-1)mũ 18
b) ( 2x-3) mũ 2= 9
c) (x-5) mũ 2 = (1-3x)mũ 2
bài 2: Chứng minh rằng:
a) 15 mũ 20 - 15 mũ 19 chia hết cho 14
b) 3 mũ 20 + 3 mũ 21+ 3 mũ 22 chia hết cho 13
c) 3+ 3 mũ 2 + 3 mũ 3+.......+ 3 mũ 2007 chia hết cho 13
7 mũ 1+ 7 mũ 2+ 7 mũ 3+.........+ 7 mũ 4n chia hết cho 400
Bài 1:
a) Ta có: \(\left(2x-1\right)^{20}=\left(2x-1\right)^{18}\)
\(\Leftrightarrow\left(2x-1\right)^{20}-\left(2x-1\right)^{18}=0\)
\(\Leftrightarrow\left(2x-1\right)^{18}\left[\left(2x-1\right)^2-1\right]=0\)
\(\Leftrightarrow\left(2x-1\right)^{18}\cdot\left(2x-2\right)\cdot2x=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=\dfrac{1}{2}\\x=1\end{matrix}\right.\)
b) Ta có: \(\left(2x-3\right)^2=9\)
\(\Leftrightarrow\left[{}\begin{matrix}2x-3=3\\2x-3=-3\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}2x=6\\2x=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=3\\x=0\end{matrix}\right.\)
c) Ta có: \(\left(x-5\right)^2=\left(1-3x\right)^2\)
\(\Leftrightarrow\left(x-5\right)^2-\left(3x-1\right)^2=0\)
\(\Leftrightarrow\left(x-5-3x+1\right)\left(x-5+3x-1\right)=0\)
\(\Leftrightarrow\left(-2x-4\right)\left(4x-6\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=-2\\x=\dfrac{3}{2}\end{matrix}\right.\)
Bài 2:
a) \(15^{20}-15^{19}=15^{19}\left(15-1\right)=15^{19}\cdot14⋮14\)
b) \(3^{20}+3^{21}+3^{22}=3^{20}\left(1+3+3^2\right)=3^{20}\cdot13⋮13\)
c) \(3+3^2+3^3+...+3^{2007}\)
\(=3\left(1+3+3^2\right)+...+3^{2005}\left(1+3+3^2\right)\)
\(=13\left(3+...+3^{2005}\right)⋮13\)
A = 4 mũ 10 x 8 mũ 15 b = 4 mũ 15 x 5 mũ 30 C = 27 mũ 16 chia 9 mũ 10 b = a = 72 mũ 3 x 54 mũ 2 chia cho 158 mũ 4 b = 3 mũ 10 x 11 + 3 mũ 10 x 5 chia 3 mũ 9 x 24
mình cũng hỏi về cái này gấp nha ai biết trả lời câu nào thì trả
8376:2 mũ 2-(2 mũ 3 x 5 mũ 2 - 2 mũ 3 x 15)+2019 mũ 0
\(8376:2^2-\left(2^3.5^2-2^3.15\right)+2019^0\)
= \(8376:4-\left(2^3.25-2^3.15\right)+1\)
=\(2094-\left(2^3.\left(25-15\right)\right)+1\)
=\(2094-\left(8.10\right)+1\)
=\(2094-80+1\)
= \(2014+1\)
=\(2015\)
Bài 1 : Tìm x
a ) ( x - 1 ) mũ 2 = 49
b ) 3 . ( 13 - x ) mũ 2 = 27
c ) 164 - ( 15 - x ) mũ 3 = 100
d ) ( x + 3 ) mũ 3 - 15 = 210
x mũ 2 : 4 = 16
a) \(\left(x-1\right)^2=49\)
\(\Rightarrow\left(x-1\right)^2=7^2=\left(-7\right)^2\)
\(\Rightarrow x-1=7\) hoặc \(x-1=-7\)
\(x=7+1=8\) \(x=-7+1=-6\)
Vậy x = 8 hoặc x = - 6
b) \(3\cdot\left(13-x\right)^2=27\)
\(\left(13-x\right)^2=27\div3=9\)
\(\Rightarrow\left(13-x\right)^2=3^2=\left(-3\right)^2\)
\(\Rightarrow13-x=3\) hoặc \(13-x=-3\)
\(x=13-3=10\) \(x=13+3=16\)
Vậy x = 10 hoặc x = 16
c) \(164-\left(15-x\right)^3=100\)
\(\left(15-x\right)^3=164-100=64\)
\(\Rightarrow\left(15-x\right)^3=4^3\)
\(\Rightarrow15-x=4\)
\(x=15-4=11\)
Vậy x = 11
d) \(\left(x+3\right)^3-15=210\)
\(\left(x+3\right)^3=210+15=225\)
\(\Rightarrow\left(x+3\right)^3=...\)
Tương tự mũ lẻ cậu nhé
e) \(x^2\div4=16\)
\(x^2=16\cdot4=64\)
\(\Rightarrow x^2=8^2=\left(-8\right)^2\)
Vậy x = 8 hoặc x = - 8
a/\(\left(x-1\right)^2\)=49
\(\left(x-1\right)^2\)=\(7^2\)
=>x-1=7
x=7+1
x=8
b/3.\(\left(13-x\right)^2\)=27
\(\left(13-x\right)^2\)=27:3
\(\left(13-x\right)^2\)=9
\(\left(13-x\right)^2\)=\(3^2\)
=>13-x=3
x=13-3
x=10
c/164-\(\left(15-x\right)^3\)=100
\(\left(15-x\right)^3\)=164-100
\(\left(15-x\right)^3\)=64
\(\left(15-x\right)^3\)=\(4^3\)
=>15-x=4
x=15-4
x=11
d/\(\left(x+3\right)^3\)-15=210
\(\left(x+3\right)^3\)=210+15
\(\left(x+3\right)^3\)=225
sai đề bài câu d hay sao ý bạn ạ
chỉ có \(\left(x+3\right)^2\)thì mới tính được
e/\(x^2\):4=16
\(x^2\)=16.4
\(x^2\)=64
\(x^2\)=\(8^2\)
=>x=8
Bài 2: Tìm x, biết
a) (x+3) mũ 2 - (x-4)(x+8) = 1
b) (x+3)(x mũ 2 - 3x + 9) -x(x-2)(x+2) = 15
c) (x-2) mũ 2 - (x+3) mũ 2 - 4(x+1) = 5
d) (2x-3)(2x+3) - (x-1) mũ 2 - 3x(x-5) = -44
e) (x-2) mũ 3 - (x-3)(x mũ 2 + 3x + 9) + 6(x+1) mũ 2 = 49
f) 5x(x-3) mũ 2 - 5(x-1) mũ 3 + 15(x+2)(x-2) = 5
g) (x+3) mũ 3 - x(3x+1) mũ 2 + (2x+1)(4x mũ 2 - 2x + 1) - 3x mũ 2 = 42
a) \(\left(x+3\right)^2-\left(x-4\right)\left(x+8\right)=1\)
\(\Leftrightarrow\left(x^2+6x+9\right)-\left(x^2+4x-32\right)-1=0\)
\(\Leftrightarrow2x=-40\)
\(\Rightarrow x=-20\)
b) \(\left(x+3\right)\left(x^2-3x+9\right)-x\left(x-2\right)\left(x+2\right)=15\)
\(\Leftrightarrow x^3+27-x^3+4x=15\)
\(\Leftrightarrow4x=-12\)
\(\Rightarrow x=-3\)
c) \(\left(x-2\right)^2-\left(x+3\right)^2-4\left(x+1\right)=5\)
\(\Leftrightarrow\left(x^2-4x+4\right)-\left(x^2+6x+9\right)-\left(4x+4\right)=5\)
\(\Leftrightarrow-14x=14\)
\(\Rightarrow x=-1\)
d) \(\left(2x-3\right)\left(2x+3\right)-\left(x-1\right)^2-3x\left(x-5\right)=-44\)
\(\Leftrightarrow4x^2-9-\left(x^2-2x+1\right)-\left(3x^2-15x\right)=-44\)
\(\Leftrightarrow17x=-34\)
\(\Rightarrow x=-2\)
e) \(\left(x-2\right)^3-\left(x-3\right)\left(x^2+3x+9\right)+6\left(x+1\right)^2=49\)
\(\Leftrightarrow x^3-6x^2+12x-8-x^3+27+6x^2+12x+6=49\)
\(\Leftrightarrow24x=24\)
\(\Rightarrow x=1\)
f) \(5x\left(x-3\right)^2-5\left(x-1\right)^3+15\left(x+2\right)\left(x-2\right)=5\)
\(\Leftrightarrow5x^3-30x^2+45x-5x^3+15x^2-15x+5+15x^2-60=5\)
\(\Leftrightarrow30x=60\)
\(\Rightarrow x=2\)
g) \(\left(x+3\right)^3-x\left(3x+1\right)^2+\left(2x+1\right)\left(4x^2-2x+1\right)-3x^2=42\)
\(\Leftrightarrow x^3+9x^2+27x+27-9x^3-6x^2-x+8x^3+1-3x^2=42\)
\(\Leftrightarrow26x=14\)
\(\Rightarrow x=\frac{7}{13}\)