maths PLEASE HELP
posted by jessie .
A mixture contains two chemicals, A and B, with masses mA and mB. The total mass of the mixture, m, remains constant. B is converted into A at a rate that
is inversely proportional to the mass of A and directly proportional to the square of the mass of B in the mixture at any time t.
Form a differential equation and
find a general expression relating the mass of A to the time t.
ive got dma/dt = mb^2/ma
is this right and if so is the next bit
mb = m - ma
so dma/dt = (m-ma)^2/ma
then i get stuck