Сокращение дробей 8 класс

1.а)...=75/50 * b⁵-⁴ * c³-⁴=3/2*b¹*c-¹=3b/2c
б)...=2b/b(b-9)=2/b-9
в)...=7(х-у)/(х-у)(х+у)=7/х+у
2.а)...=(b(3b+7)-3(b²-5))/3b²=
=(3b²+7b-3b²+15)/3b²=(7b+15)/3b²
б)...=(4p-q-4p-q)/(4p-q)(4p+q)=-2q/(16p²-q²)
в)...=(5-4у)/у(у-6)+4/у-6=
=(5-4у+4у)/у(у-6)=5/(у²-6у)
3...=(12p²-q-12p²)/4p=-q/4p
-28/4*(-0,35)=28/5,6=5
4...4/у-2/(у-5)-2у/у²-25-10/(у²-25)=
=(4(у²-25)-2(у+5)-2у²-10у)/у(у-5)(у+5)=
=(4у²-100-2у-10-2у²-10у)/у(у-5)(у+5)=
=(2у²-12у-110)/у(у-5)(у+5)=
=(2(у²-6у-55))/у(у-5)(у+5)=

(у²-6у-55=0
По теореме Виета :
у1+у2=6
у1*у2=-55
у1=11
у2=-5)
=2(у-11)(у+5)/у(у-5)(у+5=
=2(у-11)/у(у-5)=(2у-22)/(у²-5у)

75 * b^5 * c^3 / (50 * b^4 * c^4) =

= (75 / 50) * (b^5 / b^4) * (c^3 / c^4) =

= (3/2) * b^(5-4) * c^(3-4) =

= 3/2 * b * c^(-1) =

= 3/2 * b * 1/c = 3b / 2c