(а) 9m²/ 12m = 3m*3m / 3m*4 = 3m/4
(б) 15y³x⁴/ 20y²x⁵ = 5у²х⁴ *3у/5у²х⁴*4х = 3у/4х
(в) 12а³b³c / 48a⁵b³c = 12а³b³c/12a³b³c*4a² = 1/4a²
(г) (5a+10b) / 5a = 5*(a+2b) /5*a = (a+2b)/a
(д) (12m + 48n) / 48n = 12*(m+4n)/12*4n = (m+4n)/4n
(е) (x²-8x+16) / (5x - 20) = (x-4)(x-4)/5*(x-4) = (x-4)/5
(ж) (9y² - 18y) / (y²-4) = 9у*(у-2)/(у-2)(у+2) = 9у/(у+2)
(з) (y²+10y+25) / (y² - 25) = (у+5)(у+5)/(у-5)(у+5) = (у+5)/(у-5)
(и) (a - 10 )/ (a²- 20a + 100) = (а-10)/(а-10)(а-10) = 1/(а-10)
(к) (81y²-1) / (9y + 1) = (9у-1)(9у+1)/(9у+1) = 9у-1
10^(-2)=1/10^2=1/100=0,01
10^(-3)=0,001.