Explanation:
Let 'x' be the number of texts
The equation for the cost of plan A is:
[tex]y_A=40+0.4x[/tex]The equation for the cost of plan B is:
[tex]y_B=30+0.9x[/tex]We want:
[tex]y_A>y_B[/tex]Answer:
The inequality is:
[tex]40+0.4x>30+0.9x[/tex]