a: (x-3)(x-1)-x(x-2)=0

=>\(x^2-4x+3-x^2+2x=0\)

=>\(-2x+3=0\)

=>-2x=-3

=>\(x=\dfrac{3}{2}\)

b: \(\left(x+2y\right)^2-\left(2x-y\right)^2\)

\(=\left(x+2y+2x-y\right)\left(x+2y-2x+y\right)\)

\(=\left(3x+y\right)\left(-x+3y\right)\)

\(\left(2x-6\right)\times\left(5-x\right)=0\)

\(2x-6=0;5-x=0\)

\(x=3;x=5\)

Vậy: \(x=3;x=5\)

$\left(2x-6\right)\times \left(5-x\right)=0$

$2x-6=0;5-x=0$

$x\; =3,\; x\; =\; 5$

Vậy x = 3 và 5.

x=360^o-90^o-(180^o-60^o)-(180^o-105^o)=75^o

\(x=75^o\)

\(\left(X+2\right)+\left(X+4\right)+..\left(X+998\right)=250997\)

\(X+2+X+4+...+x+998=250997\)

\(\left(X+X+X+...+X\right)+\left(2+4+6+...+998\right)=250997\) 

=====================

Xét \(2+4+6+...+998\) có số lượng số hạng là:

\(\left(998-2\right):2+1=499\) (số hạng) 

Tổng của dãy số là:

\(\left(998+2\right)\times499:2=249500\) 

===============

\(\left(X+X+X+...+X\right)+\left(2+4+6+...+998\right)=250997\) 

\(499X+249500=250997\)

\(499X=250997-249500\)

\(499X=1497\)

\(X=1497:499\)

\(X=3\)

Vậy: ... 

x=105

<=> 46-x+11=-48

<=> x= 46+11+48

<=>x= 105

Vậy x=105

Chúc bạn học tốt nha!

TL:

46 - (x - 11) = - 48

=> 46 - x + 11 = - 48

=> x = 46 + 11 + 48

=> x =      105

Vậy x = 105

HT~

ĐKXĐ: \(x\le3\)

\(P=\sqrt{3-x}-\left(3-x\right)+3=-\left(\sqrt{3-x}-\dfrac{1}{2}\right)^2+\dfrac{13}{4}\le\dfrac{13}{4}\)

\(P_{max}=\dfrac{13}{4}\) khi \(\sqrt{3-x}=\dfrac{1}{2}\Leftrightarrow x=\dfrac{11}{4}\)

\(\dfrac{x+2}{-4}=-\dfrac{9}{x+2}\\ \Rightarrow\left(x+2\right)^2=\left(-4\right).\left(-9\right)\\ \Rightarrow\left(x+2\right)^2=36\\ \Rightarrow\left(x+2\right)^2=\pm6^2\\ \Rightarrow\left[{}\begin{matrix}x+2=6\\x+2=-6\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=4\\x=-8\end{matrix}\right.\)

=>(x+2)^2=36

=>x+2=6 hoặc x+2=-6

=>x=4 hoặc x=-8

\(3\left(x+3\right)=-24\)

\(x+3=-\dfrac{24}{3}\)

\(x+3=-8\)

\(x=-8-3\)

\(x=-11\)

x + 3 = -8 

x = -11

Câu này dễ nhưng e ko chx nên mn giúp e vs ạ