help me quickly !!!! thank you

Question

Ella is deciding between two cell phone plans: Which plan should she sign up for? (explain fully!)

Plan A: $35 plus 5₵/min

Plan B: $65 with unlimited minutes

Answer 1

A= 35 + .05M

B = 65

35+.05M = 65

.05M = 65-35 = 30

M = 30/.05 = 600 minutes

If she uses more than 600 minutes, she should use Plan B

if she uses less than 600 minutes, Plan A is cheaper