Question 88219
Lets assign a variable to one of the values.
x = amount of $1 tickets sold
Since the total amount of tickets sold was 739,
(739-x) = represents the amount of $1.50 tickets sold
Your equation
{{{1.00x+1.50(739-x)=857}}}
Simplify the left side
{{{-.50x+1189.50=857}}}
Subtract 1189.50 from both sides
{{{-.50x=-332.50}}}
Divide both sides by -.50
{{{x=665}}}
So, 665 $1 tickets were sold

Good luck