(HELP NEEDED) Which expression is equivalent to (6x3+3x2+8)+(2x2−9x+10)? A. 6x3+5x2−9x+18

B. 5x4+6x3−9x+18

C. 6x3+x2+9x−2

D. 8x5−6x3+18

for the first question it would be the second answer for the second question it would be the third answer and for the third question it would be the first answer

step-by-step explanation:

step-by-step explanation:

the original amount doesn't ''re just looking for the time it takes for 1/2 of the substance to we have

(1/2) =)     take the ln   of both sides

ln (1/2)   = )   and we can write

ln(1/2) = ) lne     and lne   = 1     so we have

ln(1/2) = -.1092t     divide both sides by -.1092

t = ln(1/2)/-.1092 = about 6.347 days = about 6.3 days (rounded)