ضرب الكسور — السنة الرابعة إعدادي

📐 الكسور التمرين 4 تمرين 4 من 6
4
أحسب وأعطِ النتيجة في صورة كسر مبسَّط :
\(A=\dfrac{2}{7}\times\dfrac{1}{4}\)
\(B=\dfrac{1}{5}\times\dfrac{1}{2}\)
\(C=\dfrac{-3}{-7}\times\dfrac{-9}{-2}\)
\(D=\dfrac{4}{3}\times\dfrac{-3}{4}\)
\(E=\dfrac{49}{27}\times\dfrac{70}{81}\)
\(F=\dfrac{25}{16}\times\dfrac{16}{35}\)
\(G=\dfrac{-35}{18}\times\dfrac{42}{-18}\)
\(H=\dfrac{-56}{9}\times\dfrac{-15}{28}\)
لم تبدأ بعد

💡 الخطوة 1 — تبسيط قبل الضرب

\(\dfrac{\cancelto{1}{2}}{7}\times\dfrac{1}{\cancelto{2}{4}}\)
\(\text{لا تبسيط}\)
\(\text{لا تبسيط}\)
\(\dfrac{\cancelto{1}{4}}{\cancelto{1}{3}}\times\dfrac{\cancelto{-1}{-3}}{\cancelto{1}{4}}\)
\(\text{لا تبسيط}\)
\(\dfrac{\cancelto{5}{25}}{\cancelto{1}{16}}\times\dfrac{\cancelto{1}{16}}{\cancelto{7}{35}}\)
\(\dfrac{-35}{\cancelto{3}{18}}\times\dfrac{\cancelto{7}{42}}{-18}\)
\(\dfrac{\cancelto{-2}{-56}}{\cancelto{3}{9}}\times\dfrac{\cancelto{-5}{-15}}{\cancelto{1}{28}}\)

📝 الخطوة 2 — ضرب الأعداد المبسطة

\(\dfrac{1}{7}\times\dfrac{1}{2}=\dfrac{1}{14}\)
\(\dfrac{1}{5}\times\dfrac{1}{2}=\dfrac{1}{10}\)
\(\dfrac{-3}{-7}\times\dfrac{-9}{-2}=\dfrac{27}{14}\)
\(\dfrac{1}{1}\times\dfrac{-1}{1}=\dfrac{-1}{1}\)
\(\dfrac{49}{27}\times\dfrac{70}{81}=\dfrac{3430}{2187}\)
\(\dfrac{5}{1}\times\dfrac{1}{7}=\dfrac{5}{7}\)
\(\dfrac{-35}{3}\times\dfrac{7}{-18}=\dfrac{-245}{-54}\)
\(\dfrac{-2}{3}\times\dfrac{-5}{1}=\dfrac{10}{3}\)

✅ النتيجة النهائية

\(\dfrac{1}{14}\)
\(\dfrac{1}{10}\)
\(\dfrac{27}{14}\)
\(-1\)
\(\dfrac{3430}{2187}\)
\(\dfrac{5}{7}\)
\(\dfrac{245}{54}\)
\(\dfrac{10}{3}\)