15. Find the surface area of the figure.

Well personally I would use your fomula because its different ways to do this and is taught differnet but the way I was taught was to add up all the sides and multiply

Step-by-step explanation:

add all of them

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)

.25

step-by-step explanation: