\(x^2-24x-25\)
25 / 24x 27 /5 x 2 x34 /9 x 36 /17
\(\dfrac{25}{24}\times\dfrac{27}{5}\times2\times\dfrac{34}{9}\times\dfrac{36}{17}\)
\(=(\dfrac{25}{24}\times\dfrac{54}{5})\times\left(\dfrac{34}{9}\times\dfrac{36}{17}\right)\)
\(=\dfrac{45}{4}\times2\times4\)
\(=90\)
X^2-24X-25
a, X mũ 2 - 24x-25
b,x mũ 2-y mũ 2+14x+49
a) x2-24x-25=x2+x-25x-25
=x(x+1)-25(x+1)
=(x-25)(x+1)
b) x2-y2+14x+49=(x2+14x+49)-y2
=(x+7)2-y2=(x-y+7)(x+y+7)
a)a2 – 4b2 b) x2 – y2 + 6y - 9
c) (2a + b)2 – a2 d) 16(x – 1)2 – 25(x + y)2
e)x2 + 10x + 25 f) 25x2 – 20xy + 4y2
g)9x4 + 24x2 + 16 h) x3 – 125
i)x6 – 1 k) x3 + 15x2 + 75x + 125
a) (a - 2b)x(a + 2b)
b) x2-(y-3)2
=> (x-y+3)(x+y-3)
c) (2a + b - a)(2a + b + a)
=> (a+b)(3a+b)
d) (4(x - 1))2 - (5(x + y))2
⇔ (4x - 4 - 5x - 5y)(4x - 4 + 5x + 5y)
⇔ -(x + 5y + 4)(9x + 5y + -4)
e) (x + 5)2
f) (5x - 2y)2
h) (x - 5)(x2 + 5x + 25)
k) (x + 5)3
Giải phương trình: x4 - 24x2 - 25 = 0.
Tìm x bt rằng :
a, 4x mũ 2-24x+36=(x-3)mũ 3
b, (8x mũ 3-7x mũ 2):x mũ 2=3x+căn 9 phần 25
`Answer:`
a, `4x^2-24x+36=(x-3)^3`
`<=>4(x^2-6x+9)-(x-3)^3=0`
`<=>4(x-3)^2-(x-3)^3=0`
`<=>(x-3)^2.(4-x+3)=0`
`<=>(x-3)^2.(7-x)=0`
`<=>x-3=0` hoặc `7-x=0`
`<=>x=3` hoặc `x=7`
b, `(8x^3-7x^2):x^2=3x+\sqrt{\frac{9}{25}}`
`<=>8x^3:x^2-7x^2:x^2=3x+\sqrt{\frac{9}{25}}`
`<=>8x-7=3x+\sqrt{\frac{9}{25}}`
`<=>8x-7=3x+3/5`
`<=>8x=3x+\frac{38}{5}`
`<=>8x-3x=3x+\frac{38}{5}-3x`
`<=>5x=\frac{38}{5}`
`<=>x=\frac{38}{25}`
Phân tích đa thức sau thành nhân tử:
a, x2 -y2 +14x +49
b,x2 -24x -25
á,(x+7)2-y2
= (x+7+y)(x+7-y)
b, (x+1)(x-25)
chúc bạn luôn thành công trong cuộc sống nha
a)
\(x^2-y^2+14x+49\)
\(=\left(x^2+14x+49\right)-y^2\)
\(=\left(x^2+2.7.x+7^2\right)-y^2\)
\(=\left(x+7\right)^2-y^2\)
\(=\left(x+y+7\right)\left(x-y+7\right)\)
Vậy ...
b)
\(x^2-24x-25\)
\(=x^2-24x+144-169\)
\(=\left(x^2-24x+144\right)-169\)
\(=\left(x^2-2.12.x+12^2\right)-13^2\)
\(=\left(x-12\right)^2-13^2\)
\(=\left(x-12+13\right)\left(x-12-13\right)\)
\(=\left(x+1\right)\left(x-25\right)\)
Vậy ...
tìm x thuộc Z
a) -30+ ( 25-x)= -1
b) (x+5) + ( x-9)=x+ 2
c) 30(x+2) - 6(x-5)-24x =100
d) 2(x-5) - 3(x-4)=-6+15.(-3)
a, Ta có :\(-30+\left(25-x\right)=-1\)
\(\Leftrightarrow\left(-30\right)+25-x=-1\)
\(\Leftrightarrow25-x=\left(-1\right)-\left(-30\right)\)
\(\Leftrightarrow25-x=29\\ \Leftrightarrow x=25-29\)
\(\Leftrightarrow x=\left(-4\right)\)
Vậy \(x=-4\)
b,Ta có :\(\left(x+5\right)+\left(x-9\right)=x+2\)
\(\Leftrightarrow x+5+x-9=x+2\)
\(\Leftrightarrow2.x+\left(5-9\right)=x+2\)
\(\Leftrightarrow\) \(2.x+\left(-4\right)=x+2\)
\(\Leftrightarrow2.x-x=4+2\)
\(\Leftrightarrow x=6\)
Vậy \(x=6\)
Bài 1: Thu gọn :
(x+1).(x+2)-3x.(x-4)
Bài 2: Tìm x:
(3x-4).(x-2)=3x.(x-9)
Bài 3: Chứng minh biểu thức không phụ thuộc vào giá trị của biến:
-3x.(x-4).(x-2)-x^2.(-3x+18)+24x-25
1) \(\left(x+1\right)\left(x+2\right)-3x\left(x-4\right)=x^2+3x+2-3x^2+12x=-2x^2+15x+2\)
2) \(\left(3x-4\right)\left(x-2\right)=3x\left(x-9\right)\)
\(\Leftrightarrow3x^2-10x+8=3x^2-27x\)
\(\Leftrightarrow17x=-8\Leftrightarrow x=-\dfrac{8}{17}\)
3) \(-3\left(x-4\right)\left(x-2\right)-x^2\left(-3x+18\right)+24x-25\)
\(=-3x^3+6x^2+12x^2-24x+3x^3-18x^2+24x-25=-25\)