$\frac{15a^2+10ab}{3ab+2b^2}=\frac{5a(3a+2b)}{b(3a+2b)}=\frac{5a}{b}$
при a = −2, b = 0,4:
$\frac{5\ast (-2)}{0,4}=\frac{-10}{\frac{4}{10}}=-10\ast \frac{10}{4}=-5\ast 5=-25$

$\frac{9b^2-4c^2}{12b^{2}c-8b{c}^2}=\frac{(3b-2c)(3b+2c)}{4bc(3b-2c)}=\frac{3b+2c}{4bc}$
при $b=\frac{1}{3}$, c = −6:
$\frac{3\ast \frac{1}{3}+2\ast (-6)}{4\ast \frac{1}{3}\ast (-6)}=\frac{1-12}{4\ast (-2)}=\frac{-11}{-8}=\frac{11}{8}=1\frac{3}{8}$

$\frac{36x^2-12xy+y^2}{y^2-36x^2}=\frac{(6x-y{)}^2}{(y-6x)(y+6x)}=\frac{(y-6x{)}^2}{(y-6x)(y+6x)}=\frac{y-6x}{y+6x}$
при x = 1,2, y = −3:
$\frac{-3-6\ast 1,2}{-3+6\ast 1,2}=\frac{-3-7,2}{-3+7,2}=\frac{-10,2}{4,2}=-\frac{102}{42}=-\frac{17}{7}=-2\frac{3}{7}$

$\frac{a^8-a^6}{a^9+a^8}=\frac{a^6(a^2-1)}{a^8(a+1)}=\frac{a^6(a-1)(a+1)}{a^8(a+1)}=\frac{a-1}{a^2}$
при a = −0,1:
$\frac{-0,1-1}{(-0,1{)}^2}=\frac{-1,1}{0,01}=-110$