Đáp án:
Giải thích các bước giải:
1,
a, 5x²-x
=x(5x-1)
b,x²-2xy-169+y²
=x²-2xy+y²-169
=(x-y)²-169
2, 2x(x-2)-(x-2)=0
⇒(2x-1)(x-2)=0
⇒\(\left[ \begin{array}{l}2x-1=0\\x-2=0\end{array} \right.\)
=>\(\left[ \begin{array}{l}2x=1\\x=2\end{array} \right.\)
=>\(\left[ \begin{array}{l}x=1/2\\x=2\end{array} \right.\)
b, 3x(2x-5)-4(5-2x)=0
=>3x(2x-5)+4(2x-5)=0
=>(3x+4)(2x-5)=0
\(\left[ \begin{array}{l}3x+4=0\\2x-5=0\end{array} \right.\) =>\(\left[ \begin{array}{l}3x=-4\\2x=5\end{array} \right.\) =>\(\left[ \begin{array}{l}x=-4/3\\x=5/2\end{array} \right.\)
