P+3 per 2p+10 – p+12 per p2+3p-10=…..

(p+3)/(2p+10) – (p+12)/(p²+3p-10)
= (p+3)/ 2(p+5)  - (p+12)/(p+5)(p-2) 
samakan penyebutnya dengan 2(p+5)(p-2)
= {(p+3)(p-2) – (p+12)(2) } / {2(p+5)(p-2)}
= (p²+p- 6 – 2p -24 )/ { 2(p+5)(p-2)
= (p² – p – 30) /  2(p²+ 3p-10)
= (p² -p – 30)/ ( 2p² + 6p -20)