Pauline spent $7.50 every day for 3 days. which expression is the best choice to her determine the total amount of money she spent? a. (7.50) × (−3) = −22.50; she spent $22.50. b. (−7.50) × (3) = −22.50; she spent $22.50. c. (−7.50) × (−3) = 22.50; she spent $22.50. d. (7.50) × (3) = 22.50; she spent $22.50.

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)