Task/26340622
-------------------
1.
(4a +3b)/(3a +4b) = (4a/b +3) /(3a/b +4) = (4*2 +3) /(3*2 +4) = 11/10 =1,1.
-------
( (100 - y²) /21xy ) * ( 28y² /(y² +20y +100) ) =
( (10 -y)(10+y) /21xy ) * ( 28y² /(10+y)² ) =
(10 -y)(10+y)* 28y² / 21xy(10+y)² = 4y(10 -y) /3x(10+y) .
-------
2.
a³*b /(-c⁵) *c⁴ /a²b = a³*b*c⁴ /(-c⁵)*a²*b = - a /c .
------- вряд ли -------
(100 - y²) /21xy : 28y² /(y² +20y +100) = (10 -y)(10+y) /21xy : 28y² /(10+y)² =
(10 -y)(10+y)(10+y)² / 21xy* 28y² / 21xy(10+y)² = (10 -y)(10+y)³ /588xy³ .