a varies directly as the square of b and inversely as the square of c. If a=89 when b=6 and c=6 , find a if b=4 and c = 5 . Round your answer to two decimal places if necessary

Answer 1

Direct variance is a = kb. Inverse variation is a = k/c

a = kb^2 / c^2

89 = k*6^2 / 6^2

89 = k

a = 89*4^2 / 5^2

a = 89*16/25 = 56.96