Question 1132796
Adult tickets, {{{x}}}, cost {{{5 }}} dollars and child tickets,{{{y}}} cost {{{2}}} dollars. 


The box office recorded ${{{190}}} in ticket sales. 

{{{5x+2y=190}}}....eq.1

A total of {{{50}}} tickets were sold. 
 {{{x + y = 50}}}....eq.2

solve the system:

{{{5x+2y=190}}}....eq.1
{{{x + y = 50}}}....eq.2->solve for {{{x}}}
--------------------------------------------

{{{x = 50-y}}}....eq.2
---------------------------------------------substitute in eq.1

{{{5(50-y)+2y=190}}}.->solve for {{{y}}}

{{{250-5y+2y=190}}}
{{{250-3y=190}}}
{{{250-190=3y}}}
{{{60=3y}}}
{{{y=20}}}

go to {{{x = 50-y}}}....eq.2, plug in {{{20}}} for {{{y}}}

{{{x = 50-20}}}

{{{x = 30}}}


How many of those tickets were child tickets?

answer: {{{20}}}  tickets were child tickets