C=DA/A + 12

the fomula;
A= the child age, in year
D=an adult dosage
C= the proper child dosage

when the adult dosage is 1000 milligrams, a child is given 300 milligram. What is that child's age? Round to the nearest year.

Question

C=DA/A + 12

the fomula;
A= the child age, in year
D=an adult dosage
C= the proper child dosage

when the adult dosage is 1000 milligrams, a child is given 300 milligram. What is that child's age? Round to the nearest year.

rulnick · Answer

There may be a problem with the formula as written, particularly "DA/A"

anonymous · Answer

I'm sure I wrote it's right. which it say on the book.

anonymous · Answer

if you can't find the answer then it's fine

rulnick · Answer

The problem with "DA/A" or "D times A divided by A" is that A cancels out, and it just equals D.

rulnick · Answer

Unless you are missing parentheses: DA/(A+12)?

anonymous · Answer

if that the case then I'll try either way to find the answer.

anonymous · Answer

should this equation should look like this:
C=DA/A + 12   =     300=1000/12

rulnick · Answer

In the latter case, where the denominator is A+12, you get
300 = 1000A/(A+12)
300(A+12) = 1000A
3A+36=10A
36=7A
A=36/7=5 and 1/7 years

rulnick · Answer

So, to the nearest year: 5 yrs old.

anonymous · Answer

oh that the part. Thanks