Question

Solve C = a/a+12 -A

C= CHILD DOSE IN MILLIGRAMS
a = age of child
A = adult dosage in milligrams

Answer 1

`a= (- 12 (C + A))/(C + A - 1)`

Explanation:

Assuming we want to solve:

`C=(a)/(a+12)-A`

Add A to both sides;

`C + A=(a)/(a+12)`

Cross multiply;

`(C + A)(a + 12) = a`

Expand:

`a(C + A) + 12 (C + A) = a`

Group similar terms:

`a(C + A) - a= - 12 (C + A)`

Factor:

`a((C + A) - 1)= - 12 (C + A)`

`a= (- 12 (C + A))/(C + A - 1)`