а)2(5b + a) + 3b(a + 5b)=
(2+3b)+(5b+a)
б)36a^2-60a+25-(9a^2+24a+16)=36a^2-60a+25-9a^2-24a-16=9a^2(4-1)-6a(10+4)-16+25=27a^2-84a+9
а)2(5b + a) + 3b(a + 5b)=
(2+3b)+(5b+a)
б)36a^2-60a+25-(9a^2+24a+16)=36a^2-60a+25-9a^2-24a-16=9a^2(4-1)-6a(10+4)-16+25=27a^2-84a+9