Đáp án: $(x-\dfrac{25}2-\dfrac{\sqrt{1201}}{2})(x-\dfrac{25}2+\dfrac{\sqrt{1201}}{2})$
Giải thích các bước giải:
Ta có:
$x^2-25x-144$
$=x^2-2x\cdot \dfrac{25}2+(\dfrac{25}2)^2-(\dfrac{25}2)^2-144$
$=(x-\dfrac{25}2)^2-\dfrac{1201}{4}$
$=(x-\dfrac{25}2)^2-(\dfrac{\sqrt{1201}}{2})^2$
$=(x-\dfrac{25}2-\dfrac{\sqrt{1201}}{2})(x-\dfrac{25}2+\dfrac{\sqrt{1201}}{2})$