a, 3.|x-1| + 2.|x-1| = 3. |x-1| + 4
b, ( x-3 ) 27 =( x-3 ) 127
Tìm x
A (x-3)^27=(x-3)^127
B (x-1)(x-2)=0
\(a,\left(x-3\right)^{27}=\left(x-3\right)^{127}\)
\(\Leftrightarrow\left(x-3\right)^{127}-\left(x-3\right)^{27}=0\)
\(\Leftrightarrow\left(x-3\right)^{27}\left[\left(x-3\right)^{100}-1\right]=0\)
\(\Rightarrow\orbr{\begin{cases}\left(x-3\right)^{27}=0\\\left(x-3\right)^{100}-1=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x-3=0\\\left(x-3\right)^{100}=1\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=3\\x-3=\pm1\end{cases}\Rightarrow}x\in\left\{2;3;4\right\}}\)
Vậy \(x\in\left\{2;3;4\right\}\)
\(b,\left(x-1\right)\left(x-2\right)=0\)
\(\Rightarrow\orbr{\begin{cases}x-1=0\\x-2=0\end{cases}}\Rightarrow\orbr{\begin{cases}x=1\\x=2\end{cases}}\)
Vậy \(x\in\left\{1;2\right\}\)
1. Tìm x:
a. 2x.(2x-1)^2 - 3x.(x+3).(x-3) - 4x.(x+1)^2 - x^3 = x^3 - 16.x^2 + 1
b. x.(x-2)^2 + 3x.(2x-1)^2 - 13.x^2 + 16.x^2 = 5x+2
2. Tính nhanh
a. 127^2 + 146 x 127 + 73^2
b. 9^8 x 2^8 - ( 18^4 - 1 ) x ( 18^4 + 1 )
help pls
Tìm X
A, (X+1)(X+2)(X+5) - X^2(X+8)=27
B, 1/4 X^2-(1/2X-4)1/2X=-14
C, 3(1-4X)(X-1)+4(3X-2)(X+3)=-27
D,(X+3)(X^2-3X+9) - X(X-1)(X+1)=27
Tìm x biết
a) 3(1-4x).(x-1)+4(3x-2).(x+3)=-27
b) (x+3).(x2-3+9)-.(x-1).(x+1)=27
c) 2x2+3(x-1).(x+1)=5x.(x+1)
d) 8(x-1).(x+5)-(x+2).(x+5)=3(x-1).(x+2)
Bài 1 Thực hiện các phép tính sau
1/2 - 3/5 + 1/9 + 1/127 + 7/18 - 4/35 - 2/7
1/3 - 3/4 + 3/5 + 1/57 - 1/36 + 1/15 - 2/9
Bài 2 Tìm x
3/x-7 = 27/15
Tìm x biết
a) 3(1-4x).(x-1)+4(3x-2).(x+3)=-27
b) (x+3).(x2-3+9)-.(x-1).(x+1)=27
c) 2x2+3(x-1).(x+1)=5x.(x+1)
d) 8(x-1).(x+5)-(x+2).(x+5)=3(x-1).(x+2)
a, \(3\left(1-4x\right)\left(x-1\right)+4\left(3x-2\right)\left(x+3\right)=-27\)
\(\Rightarrow3\left(x-1-4x^2+4x\right)+4\left(3x^2+9x-2x-6\right)=-27\)
\(\Rightarrow15x-3-12x^2+12x^2+28x-24=-27\)
\(\Rightarrow43x=-27+24+3\Rightarrow x=0\)
Các câu còn lại làm tương tự! Phá tan tành hoa loa kèn nhà nó ra!
Chúc bạn học tốt!!!
Bài 1:
a) 3^x=9
b) 5^x=125
c) 3^x+1=9
d) 6^x-1=36
e) 3^2x+1=27
f) x^50=x
Bài 2:
a) 2^x :4=32
b)3^x:3^2
c)5^x-1:5=5^3
d)4^2x-1:4=4^4
Bài 3:
a) (2x+1)^3=27
b) 4x^3+15=47
a. Lim x->3 x^3-27/3x^2-5x-2 b. Lim x->2 căn bậc hai (x+2)-2/4x^2-3x-2 c. Lim x->1 1-x^2/x^2-5x+4 d. Lim x->1 căn bậc ba (x+7)/x^3+27+1
a. \(lim_{x\rightarrow3}\dfrac{x^3-27}{3x^2-5x-2}=\dfrac{3^3-27}{3.3^2-5.3-2}=\dfrac{0}{10}=0\)
b. \(lim_{x\rightarrow2}\dfrac{\sqrt{x+2}-2}{4x^2-3x-2}=\dfrac{\sqrt{2+2}-2}{4.2^2-3.2-2}=\dfrac{0}{8}=0\)
c. \(lim_{x\rightarrow1}\dfrac{1-x^2}{x^2-5x+4}=lim_{x\rightarrow1}\dfrac{\left(1-x\right)\left(x+1\right)}{\left(x-1\right)\left(x-4\right)}=lim_{x\rightarrow1}\dfrac{-\left(x+1\right)}{x-4}=\dfrac{-\left(1+1\right)}{1-4}=\dfrac{2}{3}\)
d. Câu này mình chịu, nhìn đề hơi lạ so với bình thường hehe