1) 4m⁴a/ 6x² × 2x² / 4m³a² = m / 3a
2) m / 3a ÷ (10+ 2a) / 6a² = m / 3a × 6a² / 10 + 2a = 2am / 10 + 2a = 2am / 2(5+a)= am / 5 + a
3) am / 5 + a × a² - 25 / 2m² = am / a + 5 × (a + 5)(a - 5)/ 2m² = a ( a - 5)/ 2m
4) a(a - 5) / 2m × 6m/ a² - 10a + 25 = a ( a - 5)/ 2m × 6m/ (a - 5)(a - 5) = 3a/a-5
Ответ: 3a / a - 5