tìm x biết:
a. (3x^2-2^4)*2^3=2^8
b. |x-5|-2*(-3)=2^4
giúp tớ với kaka :(((
Bài 2 Tìm x biết 1, (2x-2).(3x+1)-(3x-2).(2x-3)=5 2,(1-3x).(3x-5)-(2x-4)(2-3x)=x-6 3,(2x-1).(4x^2+2x+1)-(2x+1)(4x^2-2x+1)=5x+6 Giúp tớ với
1: \(\left(2x-2\right)\left(3x+1\right)-\left(3x-2\right)\left(2x-3\right)=5\)
=>\(6x^2+2x-6x-2-\left(6x^2-9x-4x+6\right)=5\)
=>\(6x^2-4x-2-6x^2+13x-6=5\)
=>9x-8=5
=>9x=13
=>\(x=\frac{13}{9}\)
2: \(\left(1-3x\right)\left(3x-5\right)-\left(2x-4\right)\left(2-3x\right)=x-6\)
=>\(3x-5-9x^2+15x+\left(2x-4\right)\left(3x-2\right)=x-6\)
=>\(-9x^2+18x-5+6x^2-4x-12x+8=x-6\)
=>\(-3x^2+2x+3-x+6=0\)
=>\(-3x^2+x+9=0\)
=>\(3x^2-x-9=0\)
=>\(x^2-\frac13x-3=0\)
=>\(x^2-2\cdot x\cdot\frac16+\frac{1}{36}-\frac{109}{36}=0\)
=>\(\left(x-\frac16\right)^2=\frac{109}{36}\)
=>\(x-\frac16=\pm\frac{\sqrt{109}}{6}\)
=>\(x=\frac16\pm\frac{\sqrt{109}}{6}\)
3: \(\left(2x-1\right)\left(4x^2+2x+1\right)-\left(2x+1\right)\left(4x^2-2x+1\right)=5x+6\)
=>\(8x^3-1-8x^3-1=5x+6\)
=>5x+6=-2
=>5x=-8
=>\(x=-\frac85\)
Tìm số nguyên x biết
a.-5.(-x+7)-3.(-x-5)=-4.(12-x)+48
b.-2.(15-3x)-4.(-7x+8)=-5-9.(-2x+1)
c.7.(-x-7)-5.(-x-3)=12.(3-x)
d.5.(-3x-7)-4.(-2x-11)=7.(4x+10)+9
f.-2.(x+3)-15=3.(4+2x)+7
giúp tớ nhé tớ đang cần gấp help me
a. (3*x^2 - 2^4)*2^3=2^8
b. |x-5"--2*(-3)=2^4
giúp kaka :(((
\(\left(3.x^2-2^4\right)2^3=2^8\\ \left(3.x^2-2^4\right)=2^8:2^3\\ \left(3.x^2-2^4\right)=2^5\\ 3.x^2-2^4=32\\ 3.x^2=32+2^4\\ 3.x^2=48\\ x^2=48:3\\ x^2=16\\ x=+-4\)
bn ghi lại đề câu b) nhé
lx-5l-2(-3)=2^4
lx-5l+6=16
lx-5l=16-6
lx-5l=10
\(\left[{}\begin{matrix}x-5=-10\\x-5=10\end{matrix}\right.\\ =>\left[{}\begin{matrix}x=-10+5\\x=10+5\end{matrix}\right.\\ =>\left[{}\begin{matrix}x=-5\\x=15\end{matrix}\right.\)
Tìm x , biết
a)(x+2)(x-3)-(x-2)(x+5)=0
b)(2x+3)(x-4)+(x-5)(x-2)=(3x-5)(x-4)
c)(8-5x)(x+2)+4(x-2)(x+1)+2(x-2)(x+2)=0
giúp mình với nhé
Tìm x biết : (x+1)(x+2)(x-3)(x-4)=(x^2-2x-3)^2-3x^2
giúp tớ với ^_^
các bn giúp mik lm bài tìm x gấp với:
a. (x+2) (x+3)-(x-2) (x+5)= 16
b. 3x (2x-4)-2x (3x+5)= 44
c. 2 (5x-8-3) (4x-5)= 4 (3x-4)
a) ( x + 2 )( x + 3 ) - ( x - 2 )( x + 5 ) = 16
<=> x2 + 5x + 6 - ( x2 + 3x - 10 ) = 16
<=> x2 + 5x + 6 - x2 - 3x + 10 = 16
<=> 2x + 16 = 16
<=> 2x = 0
<=> x = 0
b) 3x( 2x - 4 ) - 2x( 3x + 5 ) = 44
<=> 6x2 - 12x - 6x2 - 10x = 44
<=> -22x = 44
<=> x = -2
c) 2( 5x - 8 - 3 )( 4x - 5 ) = 4( 3x - 4 )
<=> 2( 5x - 11 )( 4x - 5 ) = 4( 3x - 4 )
<=> 2( 20x2 - 69x + 55 ) = 12x - 16
<=> 40x2 - 138x + 110 = 12x - 16
<=> 40x2 - 138x + 110 - 12x + 16 = 0
<=> 40x2 - 150 + 126 = 0 ( chưa học nghiệm vô tỉ nên để vô nghiệm nha :) )
=> Vô nghiệm
a. (x+2) (x+3)-(x-2) (x+5)= 16
x2+5x+6-x2-3x+10=16
2x+16=16
2x=0
x=0
b,3x (2x-4)-2x (3x+5)= 44
6x2-12x-6x2-10x=44
-22x=44
x=-2
Ý c bạn tự lm,tương tự nhưa,b
a, \(\left(x+2\right)\left(x+3\right)-\left(x-2\right)\left(x+5\right)=16\)
\(\Leftrightarrow x^2+3x+2x+6-\left(x^2+5x-2x-10\right)=16\)
\(\Leftrightarrow8x-4=16\Leftrightarrow x=\frac{20}{8}=\frac{5}{2}\)
b, \(3x\left(2x-4\right)-2x\left(3x+5\right)=44\)
\(\Leftrightarrow6x^2-12x-\left(6x^2-10x\right)=44\Leftrightarrow-2x=44\Leftrightarrow x=-22\)
c, \(2\left(5x-8-3\right)\left(4x-5\right)=4\left(3x-4\right)\)
\(\Leftrightarrow\left(10x-22\right)\left(4x-5\right)=4\left(3x-4\right)\Leftrightarrow40x^2-50x-88x+110=0\)
\(\Leftrightarrow40x^2-138x+110=0\)( vô nghiệm )
Tìm x biết
A, 2/3 + 1/3x = -2
B, (x +1/1)2 + 5/6 = 7/8
C, ( 3x + 3/5 ) (|x| - 1/4) = 0
Giúp mình với please
a,\(\frac{1}{3}x=-2-\frac{2}{3}=\frac{-8}{3}\)
\(x=\frac{-8}{3}:\frac{1}{3}=\frac{-8}{3}.\frac{3}{1}=-8\)
\(b,\left[x+\frac{1}{1}\right]^2+\frac{5}{6}=\frac{7}{8}\)
\(\Rightarrow\left[x+1\right]^2=\frac{7}{8}-\frac{5}{6}\)
\(\Rightarrow\left[x+1\right]^2=\frac{7\cdot3}{24}-\frac{5\cdot4}{24}\)
\(\Rightarrow\left[x+1\right]^2=\frac{21}{24}-\frac{20}{24}\)
\(\Rightarrow\left[x+1\right]^2=\frac{1}{24}\)
\(\Rightarrow x\in\left\{\varnothing\right\}\)
\(c,\left[3x+\frac{3}{5}\right]\left[\left|x\right|-\frac{1}{4}\right]=0\)
\(\Rightarrow\hept{\begin{cases}3x+\frac{3}{5}=0\\\left|x\right|-\frac{1}{4}=0\end{cases}}\)
\(\Rightarrow\hept{\begin{cases}3x=0-\frac{3}{5}\\\left|x\right|=0+\frac{1}{4}\end{cases}}\)
\(\Rightarrow\hept{\begin{cases}3x=\frac{-3}{5}\\\left|x\right|=0+\frac{1}{4}\\\left|x\right|=0+\left[\frac{-1}{4}\right]\end{cases}}\)
\(\Rightarrow\hept{\begin{cases}x=\frac{-1}{5}\\x=\frac{1}{4}\\x=-\frac{1}{4}\end{cases}}\)
Vậy \(x\in\left\{-\frac{1}{5};\pm\frac{1}{4}\right\}\)
Tìm nghiệm của các đa thức sau
a)x2-2(x2-8) b)B(X)=3x-5-4(2x+3) c)M(y)=3y2-5y d) D(x)=2x2-3(x2+4)
Giúp tớ với bài khó quá ![]()
a: đặt \(x^2-2\left(x^2-8\right)=0\)
\(\Leftrightarrow16-x^2=0\)
=>x=4 hoặc x=-4
b: Đặt \(3x-5-4\left(2x+3\right)=0\)
=>3x-5-8x-12=0
=>-5x-17=0
=>-5x=17
hay x=-17/5
c: Đặt \(3y^2-5y=0\)
=>y(3y-5)=0
=>y=0 hoặc y=5/3
d: Đặt \(2x^2-3\left(x^2+4\right)=0\)
\(\Leftrightarrow-x^2-12=0\)
hay \(x\in\varnothing\)
(giải giúp e với) Bài 4: Tìm x 1.a) (x-2)²- (x+3)² - 4(x+1) = 5. b) (2x-3) (2x+3)-(x-1)²-3x (x - 5) = -44 c) (5x + 1)² - (5x + 3) (5x-3) = 30. d) (x + 3)² + (x-2) (x+2)-2(x-1)² = 7. f) (3x + 8)²= 0 g) (3x-8)² = 0 e) 6(x+1)2-2(x+1)+2(x-1) (x²+x+1) = 0
\(a.\left(x-2\right)^2-\left(x+3\right)^2-4\left(x+1\right)=5\)
\(\left(x^2-4x+4\right)-\left(x^2+6x+9\right)-4x-4=5\)
\(\left(-4x-6x\right)+\left(4-9\right)-4x-4=5\)
\(-10x-5-4x-4=5\)
\(-14x-9=5\)
\(-14x=14\Rightarrow x=-1\)
\(b.\left(2x-3\right)\left(2x+3\right)-\left(x-1\right)^2-3x\left(x-5\right)=-44\)
\(4x^2-9-\left(x^2-2x+1\right)-\left(3x^2-15x\right)=-44\)
\(4x^2-9-x^2+2x-1-3x^2+15x=-44\)
\(17x-10=-44\)
\(17x=-34\Rightarrow x=-2\)
\(c.\left(5x+1\right)^2-\left(5x-3\right)\left(5x+3\right)=30\)
\(25x^2+10x+1-\left(25x^2-9\right)=30\)
\(10x+10=30\)
\(10x=20\Rightarrow x=2\)
\(d.\left(x+3\right)^2+\left(x-2\right)\left(x+2\right)-2\left(x-1\right)^2=7\)
\(\left(x^2+6x+9\right)+\left(x^2-4\right)-2\left(x^2-2x+1\right)=7\)
\(2x^2+6x+5-2x^2+4x-2=7\)
\(10x+3=7\)
\(10x=4\Rightarrow x=\frac{4}{10}=\frac25\)
\(f.\left(3x-8\right)^2=0\)
\(3x-8=0\Rightarrow x=\frac83\)
\(e.6\left(x+1\right)^2-2\left(x+1\right)+2\left(x-1\right)\left(x^2+x+1\right)=0\)
\(6\left(x^2+2x+1\right)-2x-2+2\left(x^3-1\right)=0\)
\(6x^2+12x+6-2x-2+2x^3-2=0\)
\(2x^3+6x^2+10x+2=0\)
\(\Rightarrow x\approx-0,23\)