Question 975245
{{{Q+N=34}}}
{{{25Q+5N=490}}}
Multiply eq. 1 by 5 and subtract from eq. 2,
{{{25Q+5N-5Q-5N=490-5(34)}}}
{{{20Q=490-170}}}
{{{20Q=320}}}
{{{Q=16}}}
Then,
{{{16+N=34}}}
{{{N=18}}}