1) 3-х
2) 6х-3у
3) 4а-5в
4) 5х+4
A)
(b-a)/a²b + (3a+b)/ab² - (3a²-4b²)/a²b² =
= [b(b-a) + a(3a+b) - 3a² - 4b²] / a²b² =
= (b²-ab+3a²+ab-3a²-4b²) / a²b² =
=-3b²/a²b² = -3/a²
б)
x/(2(x-1)) - 3/(2x+2) +(x-2)/(x²-1) =
= [x(x+1) - 3(x-1) + 2(x-2)] / 2(x-1)(x+1) =
= (x²+x-3x+3+2x-4) / 2(x-1)(x+1) =
= (x²-1) / 2(x-1)(x+1) =
=(x-1)(x+1) / 2(x-1)(x+1) =1/2
(x+5y)²-(5x-y)²=((x+5y)-(5x-y))((x+5y)+(5x-y))=(x+5y-5x+y)(x+5y+5x-y)=(6y-4x)(6x+4y)
Ответ:-11а-9
Объяснение: (2а+3)(а-3)-2а(4+а)=2а²-6а+3а-9-8а-2а²=-11а-9