PLEASE HHELP!!! Bring the fraction:

Question

b/7a^2c to a denominator of 35a^3c^3

a/a-4 to a denominator of 16-a^2

Answer 1

5abc^2/35a^3c^3

multiply both numerator and denominator by 5ac^2. 5x7=35, a x a^2 = a^3, c x c^2 = c^3

a(4+a)/(16-a^2)

= (a^2 +4a)/(16-a^2)