The correct answer would be the 2nd option because it increases by a specific amount every X value.
X axis is the ones that goes left and right
(x,y)
symetric about the x axis means that the vertical distance from the x axis is the same for 2 points that are symetric about the x axis
y is height
(x,y)
(5,2)
2 is height
distance from x axis
therefor the other point is -2
(5,-2)
the other vertex is at (5,-2)
Use excel to draw the graph and add the trend, formula
Joel = j, Mark = m, Sandra = s
j + m + s = 120
m = 3j
j = 1/2 s --> s = 2j
plug in (substitute) each letter to make it in terms of only j: j + m + s = 120
j + 3j + 2j = 120
6j = 120
6j/6 = 120/6
j = 20
now plug in for the j & s equation:
s = 2j = 2(20) = 40
Therefore Sandra has 40 coins!