A is directly proportional to B when A = 12 and B = 3

A.) find a formula for A in terms of B

B.) find the value of A when B = 5

C.) find the value of B when A = 36

A) To find A in terms of B, we need to find A = xB. One given is A = 12 and B = 3. We substitute, which gives us 12 = x4. Divide both sides by 4, which gives us x = 3. This means that A = 3B.

B) For this, we can just plug in 5 as B in our equation. A = 3*5 - > A = 15.

C) We can plug in A as 36. 36 = 3B - > B = 12.