Question 1204977
<pre>
Lily is 34 years old.

{{{L=34}}}

Steve is: 

51 years younger than Bella 

{{{S = B - 51}}}


and 3 years younger than Hayley. 

{{{S = H - 3}}}


Bella is 23 years older than Lily. 


{{{B = L + 23}}}

{{{system( L=34,S = B - 51, S = H - 3 ,B = L + 23)}}}

Substitute 34 for L, erase the first equation:

{{{system(S = B - 51, S = H - 3 ,B = 34 + 23=57)}}}

Substitute 57 for B, erase the last equation:

{{{system(S = 57 - 51=6, S = H - 3)}}}

Substitute 6 for S erase the first equation:

{{{6 = H - 3}}}

How old is Hayley?

Add 6 to both sides:

{{{9=H}}}

Hayley is 9.

Edwin</pre>