Dennis thinks of a number. he adds 0.5 to that number and then multiplies the new result by 4. he then subtracts 2 and divides the number by 2. his final answer is 48. what number did dennis start with?

Let Dennis thought of a number = P

step 1:- He adds 0.5 to number , then number = P + 0.5

Step 2:- 4 is multiplied with (P + 0.5) , e.g., 4(P + 0.5) = 4P + 2

Step 3 :- 2 is Subtracted from (4P + 2) ,e.g., 4P + 2 - 2 = 4P

Step 4 :- 2 divides 4P by 2 e.g., 4P/2 = 2P

Step 5 :- his final answer is 2P = 48

⇒ 2P = 48

⇒ P = 24

Hope that help!

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)

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