2x+24 3 2x+24+3x–9
-------------- + ------- = ------------------- =
(x–3)(x+3) x+3 (x–3)(x+3)
5x+15 5(x+3) 5
= ------------- = -------------- = --------- =
(x–3)(x+3) (x–3)(x+3) (x–3)
= 5/(1997–3)=5/1994
x^2 3x–4 x^2 3x–4
-------------- – --------- = ---------- – ---------
x^2+2x+1 3x+3 (x+1)^2 3(x+1)
3x^2–3x^2–3x+4x+4 x+4
= -------------------------------- = ------------ =
3(x+1)^2 3(x+1)^2
19+4 23
= ----------- = ---------
3*20^2 1200
8a^3–b^3 8a^3+b^3
--------------------- + ---------------------- =
4a^2+2ab+b^2 4a^2–2ab+b^2
(2a–b)(4a^2+2ab+b^2)
= --------------------------------- +
(4a^2+2ab+b^2)
(2a+b)(4a^2–2ab+b^2)
+ ----------------------------------- =
(4a^2+2ab+b^2)
= 2a–b+2a+b=4a=4*0,05=0,2