Question 1074920
It should be 5N+25Q=385 ,
because the 5, the 5N, the 25, and the 25Q represent,amounts in cents, not $.
 
ONE WAY:
After that you could solve the first equation for N,
and substitute the expression found into the other equation.
N=29-Q,
5(29-Q)+25Q=385
145-5Q+25Q=385
145+20Q=385
20Q=385-145
20Q=240
{{{Q=240/20}}}--->{{{highlight(Q=12)}}}
and {{{N=29-12}}}--->{{{highlight(N=17)}}} .
 
That v way of solving a system of 2 linear equations with two variables is called substitution,
because you solve one equation for one variable,
and then substitute the expression found for the variable in the other equation.