Answer:
Nine
Step-by-step explanation:
3 dollars for children tickets : x
5 dollars for adult tickets: y
Equation is:
3x+5y=57
Where 57 is the total amount spent
x+y=15
where 15 is the total number of tickets bought
3x+5y=57
5(x+y)=5(15)
___________________
3x+5y=57
5x+5y=75
minus the equations top to bottom=
-2x= -18
x= -18/(-2)
x=9
He bought a total of 9 children tickets
The answer is 17. because if the sum of the angles are 90 and you subtract the 73 then it is 17