Question

Knowing that a is inversely proportional to b2 and when b=4 a is equal to 5, find the value of a when b=4/5

Answer 1

a = 16

Explanation:

inversely proportional

y = k/x

a = k/b

5 = k/4

solve for k

multiply by 4 on each side

20 =k

a = 20b

if b = 4/5

a = 20 * 4/5

a = 16