Step-by-step explanation:
x2^+8x=-20
9x^2=20
x^2=20-9
x^2=11
√x^2=√11
x=√11
318-47= 271 There are 271 non-fiction books in the library. just subtract 47 from 318 to get the answer.
6x^3+6x^5+12x^4=6x^3 (1+6X^2+2X)= 6X^3 [1+2X(3X+1)]
3ac(9-3b+5f) you got to do factorization