Across:
1. Some 12 are 1 down, assuming 8s of drama! (9)
6. Adam's partner is upset, which Eratosthenes took advantage of in his prime hunting days (5)
9. Lab gear modified as way to solve problem with variables (7)
10. Most courageous, but being aged, overtaken by best (7)
11. Ornamental product lit up spectacularly (5)
13. Former heart of Graceland and product of MS (5)
14. see 15
15,14,17. Hope racquet lets me play a way I can defeat 1 across (8 3 6)
17. see 15
19. Famous puzzle involves placing eight in special sequence... with last couple proving elusive (6)
20. Pines, perhaps, for nice construction with sin(1) (8)
23. Expressions involving conditions in finding square roots (3)
24. Where man's getting current? (5)
25. Loves to use rearrangement to find the answer (5)
27. Go over again, with first three going over ground level (7)
28. Try matt, empty interior (7)
30. Searches complex observations about first of minima (5)
31. Whole divisions get these and also train poorly (9)
Down:
1. Some 12 are mostly crystalline silica chip (7)
2. Slightly raise last to 120 degrees perhaps, making something heavenly (5)
3. Tribal region where Eve came from (3)
4. Terrible version of underwear in arty remodelling (8)
5. Some 12 put in charge among junior scouts (6)
6. Shakespeare famously wrote some timeless quote, so it still rocks (11)
7. Steady tense climbing before last of line come to pass (9)
8. Max possibly included in next remembrance (7)
12. Functions where mainly pool's played (11)
16. Sort 26 out in dramatic event (9)
18. Like zero degree 12, cannot change around ends of set (8)
19. Give up on obtaining formulation ultimately indicating clear roots for this type of 12! (7)
21. Hustles out inquisitive folks (7)
22. Some 12 are close to (just under) 51 (6)
26. Working toward problem, mathematical proposition (5)
29. Australian-born professor of crop rotation (3)
Solution:
QUADRATIC=SIEVE|
U=N=I=R=U=O=V=X|
ALGEBRA=BOLDEST|
R=E===V=I=I=N=R|
TULIP=EXCEL=THE|
I===O=S=S=O=U=M|
COMPLETE=SQUARE|
==A=Y=Y=C=U=T==|
QUEENS=CONIFERS|
U=L=O=L=N=E===L|
IFS=MAINS=SOLVE|
N=T=I=N=T===E=U|
TERRACE=ATTEMPT|
I=O=L=A=N=A=M=H|
COMBS=RATIONALS|
Name: 879 - Pool Party
Author: BenDR

Annos-Across:
1. D,A in QUARTIC
6. rev(EVE IS)
9. *(LAB GEAR)
10. OLD in BEST
11. *(LIT UP)
13. EX + (gra)CEL(and)
15,14,17. *(HOPE RACQUET LETS ME)
19. *SEQUEN(ce/s)
20. *(FOR NICE) + S(in)
23. acr
24. MA(I)NS
25. *LOVES
27. RETRACE with first three letters reversed
28. (m)ATT EMPT(y)
30. C + O(M)BS
31. *(ALSO TRAIN)
Annos-Down:
1. QUART(z) + IC
2. ANGLE with E raised one spot
3. tel r(RIB)al
4. VEST in *ARTY
5. IC in CUBS
6. *(QUO(t)E SO I(t) S(t)ILL)
7. EVEN +r(TAUT) + (lin)E
8. tel (n)EXT REME(mbrance)
12. *(MAINLY POOL'S)
16. *(SORT LEMMA)
18. ST in *CANNOT
19. QUI(N)T + IC
21. *HUSTLES
22. LI + NEAR
26. tel (prob)LEM MA(thematical)
29. rev(OAT)
Defs-Across:
1. Some 12 are
6. which Eratosthenes took advantage of in his prime hunting days
9. way to solve problem with variables
10. Most courageous
11. Ornamental product
13. product of MS
15, 14, 17. a way I can defeat 1 across
19. Famous puzzle involves placing eight
20. Pines, perhaps
23. Expressions involving conditions
24. Where man's getting current
25. to find the answer
27. ground level
28. Try
30. Searches
31. Whole divisions get these
Defs-Down:
1. Some 12 are
2. something heavenly
3. where Eve came from
4. Terrible version
5. Some 12
6. Shakespeare famously wrote some
7. come to pass
8. Max possibly
12. Functions
16. dramatic event
18. Like zero degree 12
19. type of 12
21. inquisitive folks
22. Some 12
26. proposition
29. Australian-born professor