Tìm x, biết 2(x-1)-3(2x+2)-4(2x+3)=16
Tìm x, biết: 2.(x-1) - 3.(2x+2) - 4.(2x+3)=16
Tìm x biết 2(x-1)-3(2x+2)-4(2x+3)=16
Ta có: \(2\left(x-1\right)-3\left(2x+2\right)-4\left(2x+3\right)=16\)
\(\Rightarrow2x-2-6x-6-8x-12=16\)
\(\Rightarrow2x-6x-8x=16+2+6+12\)
\(\Rightarrow-12x=36\)
\(\Rightarrow x=-3\)
Vậy x = -3
2x-2- 6x -6 - 8x-12=16
2x-6x-8x=2+6+12+16
-12x=36
x= -3
Bài 2: Tìm x biết:
1,x\(^2\)+4x+4=25
2,(5-2x)\(^2\)-16=0
3,(x-3)\(^3\)-(x-3)(x\(^2\)+3x+9)+9(x+1)\(^2\)=15
4,3(x+2)\(^2\)+(2x-1)\(^2\)-7(x-3)9x+3)=36
5,(x-3)(x\(^2\)+3x+9)+x(x+2)(2-x)=1
6,(2x+1)\(^2\)-4(x+2)\(^2\)=9
7,(x+3)\(^{^{ }2}\)-(x-4)(x+8)=1
1: =>x^2+4x-21=0
=>(x+7)(x-3)=0
=>x=3 hoặc x=-7
2: =>(2x-5-4)(2x-5+4)=0
=>(2x-9)(2x-1)=0
=>x=9/2 hoặc x=1/2
3: =>x^3-9x^2+27x-27-x^3+27+9(x^2+2x+1)=15
=>-9x^2+27x+9x^2+18x+9=15
=>18x=15-9-27=-21
=>x=-7/6
6: =>4x^2+4x+1-4x^2-16x-16=9
=>-12x-15=9
=>-12x=24
=>x=-2
7: =>x^2+6x+9-x^2-4x+32=1
=>2x+41=1
=>2x=-40
=>x=-20
Tìm x nguyên biết (3/2)^2x-1=(3/4)^5x-4; 16/2x=2
b: =>2x=16/2=8
=>x=4
a: Sửa đề: (3/2)^2x-1=(3/2)^5x-4
=>2x-1=5x-4
=>-3x=-3
=>x=1
Tìm x biết
2(x-1)-3(2x+2)-4(2x+3)=16
Tìm x, biết :
a, 2(x-1) - 3(2x+2) - 4(2x+3)=16
A) \(2\left(x-1\right)-3\left(2x+2\right)-4\left(2x+3\right)=16\)
\(2x-2-6x-6-8x-12=16\)
\(2x-6x-8x-\left(2+6+12\right)=16\)
\(x.\left(2-6-8\right)-20=16\)
\(x.\left(-12\right)=16+20\)
\(x.\left(-12\right)=36\)
\(x=36:\left(-12\right)\)
\(x=-3\)
~~ học tốt ~~!!!! >-^
1)Tìm x biết
2(x-1)-3(2x-2)-4(2x+3)=16
Tìm x biết:
a) ( x – 1 ) 3 + ( 2 – x ) ( 4 + 2 x + x 2 ) + 3x(x + 2) = 16;
b) (x + 2)( x 2 – 2x + 4) – x( x 2 – 2) = 15.
a) Rút gọn được VT = 9x + 7. Từ đó tìm được x = 1.
b) Rút gọn được VT = 2x + 8. Từ đó tìm được x = 7 2 .
Bài 2: Tìm x, biết: a) (x+2)(x² -2x+4)-x(x²+2)=15 b) (x-2)³-(x-4)(x² + 4x+16) + 6(x+1)=49 c) (x - 1)³ + (2 - x)(4 + 2x + x²)+ 3x(x + 2) = 16 d) (x - 3)³ - (x - 3)(x² + 3x + 9) + 9(x + 1)² = 15
a: Ta có: \(\left(x+2\right)\left(x^2-2x+4\right)-x\left(x^2+2\right)=15\)
\(\Leftrightarrow x^3+8-x^3-2x=15\)
\(\Leftrightarrow2x=-7\)
hay \(x=-\dfrac{7}{2}\)
b: Ta có: \(\left(x-2\right)^3-\left(x-4\right)\left(x^2+4x+16\right)+6\left(x+1\right)^2=49\)
\(\Leftrightarrow x^3-6x^2+12x-8-x^3+64+6\left(x+1\right)^2=49\)
\(\Leftrightarrow-6x^2+12x+56+6x^2+12x+6=49\)
\(\Leftrightarrow24x=-13\)
hay \(x=-\dfrac{13}{24}\)