The formulas are used in medicine to estimate the body surface area A, in square meters, of infants and children whose weight w ranges between 3 and 30 kilograms and whose height h is measured in centimeters.Based on Current's formula, what is w in terms of A ?

Explanation

To solve for w in terms of A, start with the given formula A = 4 + w / 30. Multiply both sides by 30 to eliminate the fraction, resulting in 30A = 4 + w. Then, subtract 4 from both sides to isolate w, yielding w = 30A − 4. Option A is correct because it follows these steps correctly. Options B, C, and D each involve incorrect operations or rearrangements that do not accurately reflect the process of isolating w.