tìm x biết
a, (3x+1)3 = -216
b, 3x-1+5.3x-1=162
Tìm x
a) 5x+5x+2=650
b) 3x.1+5.3x.1=162
\(a,5^x+5^{x+2}=650\\ \Rightarrow a,5^x+5^x.25=650\\ \Rightarrow26.5^x=650\\ \Rightarrow5^x=25\\ \Rightarrow5^x=5^2\\ \Rightarrow x=2\)
\(b,3^{x.1}+5.3^{x.1}=162\\ \Rightarrow3^x+5.3^x=162\\ \Rightarrow6.3^x=162\\ \Rightarrow3^x=27\\ \Rightarrow3^x=3^3\\ \Rightarrow x=3\)
a: \(\Leftrightarrow5^x=25\)
hay x=2
a, <=> 5x + 5x .52 =650
<=> 5x +25.5x =650
<=> 26.5x =650
<=> 5x =25
<=> 5x = 52
<=> x=2
b, <=> 6. 3x =162
<=> 3x =27
<=> 3x =33
<=> x=3
Chúc bạn học tốt nha!
b1:So Sánh
a)53 và 35 b) (273) và 2712 c) 324 và 277
b2 tìm số tự nhiên x, biết
a)x3=216
b)3x + 15=18
`1a)5^3` và `3^5`
`5^3=125`
`3^5=243`
Vì `243>125` nên `3^5>5^3`
__
`c)3^24` và `27^7`
`27^7=(3^3)^7=3^21`
Vì `3^24>3^31` nên `3^24>27^7`
`2a)x^3=216`
`=>x^3=6^3`
`=>x=6`
__
`b)3^x+15=18`
`=>3^x=18-15`
`=>3^x=3`
`=>x=1`
tìm x biết
a) 3x(x-1)+5(x-1)=0
b) x2-3x+2=0
a) \(\Rightarrow\left(x-1\right)\left(3x+5\right)=0\Rightarrow\left[{}\begin{matrix}x=1\\x=-\dfrac{5}{3}\end{matrix}\right.\)
b) \(\Rightarrow x\left(x-1\right)-2\left(x-1\right)=0\Rightarrow\left(x-1\right)\left(x-2\right)=0\Rightarrow\left[{}\begin{matrix}x=1\\x=2\end{matrix}\right.\)
tìm x , biết
a. 4x(x-5)-(x-1)(4x-3)=5
b. (3x-4)(x-2) = 3x(x-9)-3
c.2(x+3)-x2 -3x=0
d. 8x3-50x=0
e. (4x-30)2-3x(3-4x)
\(a,\Rightarrow4x^2-20x-4x^2+3x+4x-3=5\\ \Rightarrow-13x=8\Rightarrow x=-\dfrac{8}{13}\\ b,\Rightarrow3x^2-10x+8-3x^2+27x=-3\\ \Rightarrow17x=-11\Rightarrow x=-\dfrac{11}{17}\\ c,\Rightarrow\left(x+3\right)\left(2-x\right)=0\Rightarrow\left[{}\begin{matrix}x=-3\\x=2\end{matrix}\right.\\ d,\Rightarrow2x\left(4x^2-25\right)=0\\ \Rightarrow2x\left(2x-5\right)\left(2x+5\right)=0\Rightarrow\left[{}\begin{matrix}x=0\\x=\dfrac{2}{5}\\x=-\dfrac{2}{5}\end{matrix}\right.\\ e,Sửa:\left(4x-3\right)^2-3x\left(3-4x\right)=0\\ \Rightarrow\left(4x-3\right)^2+3x\left(4x-3\right)=0\\ \Rightarrow\left(4x-3\right)\left(7x-3\right)=0\Rightarrow\left[{}\begin{matrix}x=\dfrac{3}{4}\\x=\dfrac{3}{7}\end{matrix}\right.\)
a.
4x(x-5) - (x-1)(4x-3)-5=0
4x^2-20x-4x^2+3x+4x+3=0
(4x^2-4x^2)+(-20x+3x+4x)+3=0
13x+3 = 0
13x=-3
x=-3/13
b,
(3x-4)(x-2)-3x(x-9)+3=0
3x^2-6x-4x+8 - 3x^2+27x+3=0
(3x^2-3x^2)+(-6x-4x+27x)+(8+3)=0
17x+11=0
17x=-11
x=-11/17
c, 2(x+3)-x^2-3x=0
2(x+3) - x(x+3)=0
(x+3)(2-x)=0
TH1: x+3 = 0; x=-3
TH2: 2-x=0;x=2
Tìm x biết
a) -2x(x+3)+x(2x-1)=10
b) (2/3x)(9x/2+1/4)-(3x2x+2)=3
a: -2x(x+3)+x(2x-1)=10
=>-2x^2-6x+2x^2-x=10
=>-7x=10
=>x=-10/7
b: Sửa đề: 2/3x(9/2x+1/4)-(3x^2+2)=3
=>3x^2+1/6x-3x^2-2=3
=>1/6x-2=3
=>x=30
Tìm x, biết
a) / 3x-2 / = 4
b) / 5x-3 / = / 7-x /
c) 2 - / x-1 /- 3x = 7
d) / 2x+3 / + 2x = -4
giúp em zới gấp lắm rồi ạ!!! ;-;
a: \(\left|3x-2\right|=4\)
\(\Leftrightarrow\left[{}\begin{matrix}3x-2=4\\3x-2=-4\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=2\\x=-\dfrac{2}{3}\end{matrix}\right.\)
b: Ta có: \(\left|5x-3\right|=\left|x-7\right|\)
\(\Leftrightarrow\left[{}\begin{matrix}5x-3=x-7\\5x-3=7-x\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}4x=-4\\6x=10\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-1\\x=\dfrac{5}{3}\end{matrix}\right.\)
tìm x biết
a, -5 (x^2 - 3x + 1 ) + x ( 1 +5x) = x-2
b,-4x ( x - 5 ) + 7x (x - 4 ) - 3x^ 2 = 12
Lời giải:
a.
PT $\Leftrightarrow -5x^2+15x-5+x+5x^2=x-2$
$\Leftrightarrow 16x-5=x-2$
$\Leftrightarrow 15x=3$
$\Leftrightarrow x=\frac{3}{15}=\frac{1}{5}$
b.
PT $\Leftrightarrow -4x^2+20x+7x^2-28x-3x^2=12$
$\Leftrightarrow -8x=12$
$\Leftrightarrow x=\frac{-3}{2}$
Tìm x biết
a) 2x - 24.27.32 = 0.
b) b) 3x + 3x+2 = 270.
c) 6 ⁝ x+1
a.\(2^x-2^4.2^7.32=0\)
\(2^x-2^{16}=0\)
\(=>x=16\)
b.\(3^x+3^{x+2}=270\)
\(3^x+3^x.3^2=270\)
\(3^x.10=270\)
\(3^x=27\)
\(=>x=3\)
3x+1+5.3x+2=144
(x+1;x+2 là số mũ nhé bạn)
mà 3x+2 là riêng x thôi hay cả 3x ậy bạn
theo tớ là riêng x thôi. mà đề bài là dấu cộng mà.
Bài 1:Thực hiện phép tính
a,(5-2x)(x+3)-4x(x+2) b,(3x+1)(x-3)-4(x+2)(x-2)
c,3(x-4)(x+3)+(x-5)(x+3) d,2x(x-4)+(3x-1)(2x-5)
Bài 2:Tìm x biết
a,5x(x+3)-(5x+2)(x+3)=7
b,(3x-1)(3x+2)-9(x+2)(x-2)=10
c,(x+1)(2x-5)+2(3-x)(x+2)=7
d,(1-3x)(x+2)+3x(x-5)=8