Mryntu

this my latex code for the equation

beginequation nonumber
 q^*_1 =fractextnumber of women who had their second birth in 1971textnumber of women who had their first birth in 1970 textbf- number of women had their second birth in 1970
 end equation 

help me to write denominator as given in pic.

A simple way is to use array for the denominator

beginequation nonumber
 q^*_1 =fractextnumber of women who had their second birth in 1971
 beginarrayc
 textnumber of women who had\
 texttheir first birth in 1970 
 endarray
 -
 beginarrayc
 textnumber of women who had\
 texttheir second birth in 1970 
 endarray
 
 endequation 

An approach with parbox

documentclassarticle
usepackageamsmath
begindocument


beginequation nonumber
 q^*_1 =fractextnumber of women who had their second birth in 1971textparbox4.5cmcentering number of women who had their first birth in 1970 - textparbox4cmcentering number of women had their second birth in 1970
 end equation 

enddocument

Of course the lengths could be different to fit your sizes...

Here is a competety different approach using variables instead of the text:

documentclassarticle
usepackageamsmath

begindocument
beginalign*
 q^*_1 &=fracAB-C \
 textwhere~A &= textnumber of women who had their second birth in 1971 \
 B &= textnumber of women who had their first birth in 1970 \
 C &= textnumber of women who had their second birth in 1970 \
endalign* 
enddocument

For a horizontally centered equation one could use something like the following:

documentclassarticle
usepackageamsmath

begindocument

beginequation
 q^*_1 =fracAB-C nonumber
endequation 
beginalign*
 textwhere~A &= textnumber of women who had their second birth in 1971 \
 B &= textnumber of women who had their first birth in 1970 \
 C &= textnumber of women who had their second birth in 1970 \
endalign*
enddocument

Just to throw in an alternative layman's view

documentclassstandalone
usepackageamsmath
begindocumenthuge
$q^*_1 = textnumber of women who had their ( frac 2^ndtext birth in 1971 1^sttext birth in 1970~-~ 2^ndtext birth in 1970$)
enddocument