tìm x biết x > 0
\(1^3+2^3+3^3+.....+24^3=x^2\)
Tìm x biết: (x-3)^2-16=0
x^2 -2x=24
(2x+1)+(x+3)^2(x+7)(x-7)=0
x^2 -2x = 24
=> x^2 - 2x - 24=0
=>x^2 -8x+6x - 24 = 0
=> ( x^2- 8x)+( 6x-24) = 0
=> x(x-8) + 6(x-8) = 0
=> (x+6)(x-8)=0
=>\(\orbr{\begin{cases}x=-6\\x=8\end{cases}}\)
\(=\frac{\left(2.5\right)^4.3^4-2^4\left(3.5\right)^2}{2^8.5^2.3^3}=\frac{2^4.3^2.5^2\left(5^2.3^2-1\right)}{2^8.5^2.3^3}=\frac{255-1}{16.3}=\frac{14}{3}\)
a) Tìm x biết (x + 3)2 = (x + 3)(x – 3)
b) Chứng tỏ A = (x + 1)(x +2)(x + 3)(x + 4) – 24 chia hết cho x (với x ≠ 0)
Ta có:\(\left(x+3\right)^2=\left(x+3\right)\left(x-3\right)\)
Xét \(x+3=0\Rightarrow x=-3\)
Xét \(x+3\ne0\) ta có:
\(x+3=x-3\)
\(\Rightarrow0=6\left(VL\right)\)
Vậy \(x=-3\)
a)
(x + 3)2 = (x + 3)(x – 3)
⇔ (x + 3)2 - (x + 3)(x - 3) = 0
⇔ (x + 3)(x + 3 - x + 3) = 0
⇔ 6(x + 3) = 0
⇔ x = -3
Vậy: x = -3
b) Ta có A = (x + 1)(x + 2)(x + 3)(x + 4) – 24
= (x + 1)(x + 4)(x + 2)(x + 3) - 24
= (x2 + 5x + 4)(x2 + 5x + 6) - 24(*)
Đặt x2 + 5x + 5 = t
Thay x2 + 5x + 5 = t vào (*) ta được:
A = (t - 1)(t + 1) - 24
= t2 - 25
= (t - 25)(t + 25)
= (x2 + 5x + 5 + 5)(x2 + 5x + 5 - 5)
= (x2 + 5x + 10)(x2 + 5x)
(x2 + 5x + 10).x(x + 5) chia hết cho x (Với x ≠ 0)
Vậy: A chia hết cho x (Với x ≠ 0)
a) (x + 3)2 = (x + 3)(x - 3)
<=> x2 + 6x + 9 = x2 - 32
<=> x2 + 6x + 9 = x2 - 9
<=> 6x + 9 = -9
<=> 6x = -9 - 9
<=> 6x = -18
<=> x = -3
=> x = -3
Tìm x, biết:
a, (x-3)^2-4=0
b, x^2-2x=24
c,(2x-1)^2+(x+3)^2-5(x+7)(x-7)=0
b/ x2-2x=24
=> x2-2x-24=0
=> (x-6)(x+4)=0
=>x=6 hoặc x =-4
a/ (x-3)2 - 4 = 0
=> (x-3-2)(x-3+2)=0
=> (x-5)(x-1)=0
=> x = 5 hoặc x=1
Tìm x biết rằng:
a) ( x 2 + 2x + 4)(2 - x) + x(x - 3)(x + 4) - x 2 + 24 = 0;
b) x 2 + 3 ( 5 − 6 x ) + ( 12 x − 2 ) x 4 + 3 = 0 .
Tìm x biết:
1-(\(5\dfrac{3}{8}\)+x\(-7\dfrac{5}{24}\)):(\(-16\dfrac{2}{3}\))=0
`1-(5 3/8+x-7 5/24):(-16 2/3)=0`
`=>1-(5+3/8+x-7-5/24):(-50/3)=0`
`=>1=(x-2-11/6):(-50/3)`
`=>1=(x-11/6):(-50/3)`
`=>x-11/6=-50/3`
`=>x=-89/6`
Vậy `x=-89/6`
\(1-\left(5\dfrac{3}{8}+x-7\dfrac{5}{24}\right):\left(-16\dfrac{2}{3}\right)=0\)
\(\Leftrightarrow1-\left(\dfrac{43}{8}+x-\dfrac{173}{24}\right):\dfrac{50}{3}=0\)
\(\Leftrightarrow1-\left(\dfrac{129}{24}-\dfrac{173}{24}+x\right).\dfrac{3}{50}=0\)
\(\Leftrightarrow1+\dfrac{11}{6}-x.\dfrac{3}{50}=0\)
\(\Leftrightarrow\dfrac{17}{6}-x.\dfrac{3}{50}=0\)
\(\Leftrightarrow x.\dfrac{3}{50}=\dfrac{17}{6}\)
\(\Leftrightarrow x=\dfrac{425}{9}\)
-Chúc bạn học tốt-
\(1-\left(5\dfrac{3}{8}+x-7\dfrac{5}{24}\right):\left(-16\dfrac{2}{3}\right)=0\)
\(1-\left(\dfrac{43}{8}:\dfrac{-50}{3}+x:\dfrac{-50}{3}-\dfrac{173}{24}:\dfrac{-50}{3}\right)=0\)
\(1-\dfrac{-129}{400}-x:\dfrac{-50}{3}+\dfrac{-173}{400}=0\)
\(\left(1+\dfrac{129}{400}+\dfrac{-173}{400}\right)-x:\dfrac{-50}{3}=0\)
\(\dfrac{89}{100}-x:\dfrac{-50}{3}=0\)
\(x:\dfrac{-50}{3}=\dfrac{89}{100}-0\)
\(x:\dfrac{-50}{3}=\dfrac{89}{100}\)
\(x=\dfrac{89}{100}.\dfrac{-50}{3}\)
\(x=\dfrac{-89}{6}\)
tìm x biết (x+1)(x+2)(x+3)(x+4)-24=0
Bài 1: Tìm x
x-7/12.x=5/24-3/8.x
(x-1/2).(-3-x/2)=0
x-3/-2=-8/x-3
=) (x-3).(x-3)=(-2).(-8)
(x-3) mũ 2 =16
\(a,x-\dfrac{7}{12}x=\dfrac{5}{24}-\dfrac{3}{8}x\)
\(\Leftrightarrow\dfrac{5}{12}x+\dfrac{3}{8}x=\dfrac{5}{24}\)
\(\Leftrightarrow\dfrac{19}{24}x=\dfrac{5}{24}\Leftrightarrow x=\dfrac{5}{19}\)
Vậy x = 5/19
\(b,\left(x-\dfrac{1}{2}\right)\left(-3-\dfrac{x}{2}\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x-\dfrac{1}{2}=0\\-3-\dfrac{x}{2}=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{1}{2}\\x=-6\end{matrix}\right.\)
Vậy x = 1/2 hoặc x = -6
\(c,\dfrac{x-3}{-2}=\dfrac{-8}{x-3}\)
\(\Leftrightarrow\left(x-3\right)^2=16\)
\(\Leftrightarrow\left[{}\begin{matrix}x-3=4\\x-3=-4\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=7\\x=-1\end{matrix}\right.\)
Vậy x = 7 hoặc x = -1
bài 9:tìm x
1) (x-3)^2-4=0
2) x^2-2x=24
3) (2x-1)^2+(x+3)^3-5(x+7)(x-7)=0
giúp mình với mn ơi
1) \(\left(x-3\right)^2-4=0\)
\(\Leftrightarrow\left(x-3-2\right)\left(x-3+2\right)=0\)
\(\Leftrightarrow\left(x-5\right)\left(x-1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=5\\x=1\end{matrix}\right.\)
2) \(x^2-2x=24\)
\(\Leftrightarrow x^2-2x-24=0\)
\(\Leftrightarrow x^2+4x-6x-24=0\)
\(\Leftrightarrow x\left(x+4\right)-6\left(x+4\right)=0\)
\(\Leftrightarrow\left(x+4\right)\left(x-6\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=6\\x=-4\end{matrix}\right.\)
Bài 2: Tìm x, y, z biết
a, x - 1 / 1 = y - 2 / 2 = z - 3 / 3 và x + y + z = 24
b, x + 1 / 2 = y - 3 / -1= z + 5 / 3 và x + 2y + 3z + 23 = 0
Tìm x, biết: a) x = 1/4 + 5/13 b) x/3 = 2/3 + -1/7 c) x/3 = 16/24 + 24/ 36
d) x/15 = 1/5 + 2/3
\(a)x=\dfrac{1}{4}+\dfrac{5}{13}=\dfrac{33}{52}.\\ b)\dfrac{x}{3}=\dfrac{2}{3}+\dfrac{-1}{7}.\\ \Leftrightarrow\dfrac{x}{3}=\dfrac{11}{21}.\\ \Leftrightarrow\dfrac{7x}{21}=\dfrac{11}{21}.\\ \Rightarrow7x=11.\\ \Leftrightarrow x=\dfrac{11}{7}.\\ c)\dfrac{x}{3}=\dfrac{16}{24}+\dfrac{24}{36}=\dfrac{2}{3}+\dfrac{2}{3}=\dfrac{4}{3}.\\ \Rightarrow x=4.\\ d)\dfrac{x}{15}=\dfrac{1}{5}+\dfrac{2}{3}=\dfrac{13}{15}.\\ \Rightarrow x=13.\)