Question 365353
Let {{{a}}} = number of adult tickets sold
Let {{{b}}} = number of children's tickets sold
given:
(1) {{{7a + 5b = 1120}}}
(2) {{{a + b = 200}}}
Multiply both sids of (2) by {{{5}}} and subtract
from(1)
(1) {{{7a + 5b = 1120}}}
(2) {{{-5a - 5b = -1000}}}
{{{2a = 120}}}
{{{a = 60}}}
and
{{{ + b = 200}}}
{{{b = 200 - 60}}}
{{{b = 140}}}
60 adult tickets and 140 children's tickets were sold