The answer is x^2+9x+9. It is the only one in which all three numbers' square roots can be taken and still make a trinomial of whole numbers.
used to represent their language
Let “x” be the cost of an adult ticket
let “y” be the cost of a child ticket
1st day: 50=6x+8y
2nd day: 53=7x+8y
Let both equations equal 0
0=6x+8y-50
0=7x+8y-53
Let equation 1 =equation 2
6x+8y-50=7x+8y-53
Isolate x
7x-6x=53-50+8y-8y
x=3
substitute x=3 into equation 1
6(3)+8y=50
y=4
Therefore the cost of a child ticket is $3 and the cost of an adult ticket is $4