tolong yaa yang bisa aja..

12.) PC=½TC=½×14√2=7√2
AC =√AB²+BC²=√14²+14²=√196+196=√392=√196.2=14√2

A ke TC (AP) = √AC²+PC² = √(14√2)²+(7√2)² = √196.2+49.2 = √392+98 = √490 = 7√10 cm

13.) HD ke FB = HF atau BF sisi diagonalnya, sehingga
HF = √FG²+GH² = √18²+18² = √324+324 = √648 = √324.2 = 18√2

14.) OC=½CG=½×8=4 cm
AC =√8²+8² = √64+64 = √128 = √64.2 = 8√2
AO = √AC²+OC² = √(8√2)²+4² = √64.2+16 = √128+16 = √144 = 12 cm

15.) AC = √AB²+BC² = √24²+6² = √576+36 = √612 = √9.68 = 3√68 = = 3√4.17 =3.2√17 = 6√17
AG = √AC²+CG² = √(6√17)²+8² = √612+64 = √676 = 26 cm

16.) lim x-->-3 (x²-9)/(x²+x-6) = (2x)/(2x+1) = (2.-3)/(2.-3+1) = -6/(-6+1) = -6/-5 = 6/5 ..

17.) lim x-->~ (9x²+5x-6)/(3x²-7x-5) = lim x-->~ ((9x²/x²)+(5x/x²)-(6/x²))/((3x²/x²)-(7x/x²)-(5/x²)) = (9+0-0)/(3-0-0 = 9/3 = 3 ..

Semoga bermanfaat .. Itu kalo saya gak salah hitung, kalo salah hapus saja ..