Ответ:
Разложим на множители: \(5a+5b=5(a+b)\), \(a^2-b^2=(a-b)(a+b)\), \(x^2-y^2=(x-y)(x+y)\), \(x^2-xy=x(x-y)\), \(2x-2y=2(x-y)\), \(zt+z^2=z(z+t)\), \(z^2-t^2=(z-t)(z+t)\).
- \(\frac{a-b}{5(a+b)}\cdot\frac{a^2}{(a-b)(a+b)}=\frac{a^2}{5(a+b)^2}\).
- \(\frac{y^3}{(x-y)(x+y)}\cdot\frac{x^2-xy+y^2}{x(x-y)}=\frac{y^3(x^2-xy+y^2)}{x(x-y)^2(x+y)}\).
- \(\frac{xy}{(x-y)(x+y)}\cdot\frac{x+y}{2(x-y)}=\frac{xy}{2(x-y)^2}\).
- \(\frac{z^2+tz+t^2}{z(z+t)}\cdot\frac{3t}{(z-t)(z+t)}=\frac{3t(z^2+tz+t^2)}{z(z-t)(z+t)^2}\).
Ответ: а) \(\frac{a^2}{5(a+b)^2}\); б) \(\frac{y^3(x^2-xy+y^2)}{x(x-y)^2(x+y)}\); в) \(\frac{xy}{2(x-y)^2}\); г) \(\frac{3t(z^2+tz+t^2)}{z(z-t)(z+t)^2}\).
