Create two equations to represent each plan
On your two axes, y represents money spent, x represents number of texts sent.
First: y = 0.02x + 10
Second: y = 0.05x + 8
To find the intersection point of two graphs substitute them into each other.
0.02x + 10 = 0.05x + 8
0.02x + 2 = 0.05x Subtract 8 from both sides
2 = 0.03x Subtract 0.02x from both sides
x = 2 / 0.03 Divide both sides by 0.03
x = 66.6666... Texts must be a whole number technically, but as it asks for the exact intersect I would put this into a fraction and say 66 2/3 texts
