x' =20x-100
a) x^2 + 20x + 100
b) x^2 - 20xy + 100y^2
c) x^2 - 20x + 100
a, \(x^2+20x+100\)
\(=x^2+10x+10x+100\)
\(=x.\left(x+10\right)+10.\left(x+10\right)=\left(x+10\right)^2\)
b, \(x^2-20xy+100y^2\)
\(=x^2-10xy-10xy+100y^2\)
\(=x.\left(x-10y\right)-10y.\left(x-10y\right)=\left(x-10y\right)^2\)
c, \(x^2-20x+100\)
\(=x^2-10x-10x+100\)
\(=x.\left(x-10\right)-10.\left(x-10\right)=\left(x-10\right)^2\)
Chúc bạn học tốt!!!
a) $x^2+20x+100=x^2=2.10x+10^2=(x+10)^2$
b) $x^2-20xy+100y^2=x^2-2.x.10y+(10y)^2=(x+10y)^2$
c) $x^2-20x+100=x^2-2.10x+10^2=(x-10)^2$
tìm x biết :(x-5)30/100=20x/100+5
Ta có thể viết thành: (x - 5)3/10 = x/5 + 5
Nhân hai vế với 10, ta có : 3(x - 5) = (x/5 + 5) * 10
3x - 15 = 2x + 50
3x = 2x + 50 = 2x + 65
3x - 2x = 65
x = 65
Chúc bạn ht ~~
(x-5). 30\100 = 20x\100 + 5
(x-5) . 30/100 =20x/100+5
Cho \(P\left(x\right)=x^{100}-4x^{99}-20x^{98}-4x^{97}-20x^{96}-...-4x^3-20x^2-4x\). Tính \(P\left(7\right)=...\)
\(x=7\Rightarrow\left\{{}\begin{matrix}4=x-3\\20=3x-1\end{matrix}\right.\)\(\Rightarrow P\left(7\right)=x^{100}-4x^{99}-20x^{98}-4x^{97}-...-20x^2-4x\\ =x^{100}-\left(x-3\right)x^{99}-\left(3x-1\right)x^{98}-\left(x-3\right)x^{97}-...-\left(3x-1\right)x^2-\left(x-3\right)x\\ =x^{100}-x^{100}+3x^{99}-3x^{99}+x^{98}-x^{98}+3x^{97}-...-3x^3+x^2-x^2+3x\\ =3x\\ =21\)
(x-50).30/100=20x/100+5
---tìm x giùm tui nhoa m.n----
tim so tu nhien x biet
(x-5)30/100=20x/100+5
cho
P(x)= x100 - 4x99 -20x98-4x97-20x96-...-4x3-20x2-4x
tính P(7)
cho
P(x)= x100 - 4x99 -20x98-4x97-20x96-...-4x3-20x2-4x
tính P(7)