✅ التصحيح المفصّل
الخطوة 1 — نلاحظ العامل المشترك \left(\dfrac{2}{5}x + 5\right)
\( 2\left(\dfrac{2}{5}x + 5\right)\left(x + 4\right) - \left(\dfrac{2}{5}x + 5\right)^{2} \)
\( = \left(\dfrac{2}{5}x + 5\right)\left[2\left(x + 4\right) - \left(\dfrac{2}{5}x + 5\right)\right] \)
الخطوة 2 — نبسّط القوس الداخلي
\( 2\left(x + 4\right) - \left(\dfrac{2}{5}x + 5\right) \)
\( = 2x + (8) - \dfrac{2}{5}x - 5 \)
\( = \dfrac{8}{5}x + (3) \)
\( \left(\dfrac{2}{5}x + 5\right)\left(\dfrac{8}{5}x + 3\right) \)