Answer : The number of text messages that will result in the exact same charge from both companies is, 500
Step-by-step explanation :
Let the number of text messages be, 'x'
Cell phone company A charges $20 per month plus $0.05 per text message. Thus, the equation will be:
............(1)
Cell phone company B charges $10 per month plus $0.07 per text message. Thus, the equation will be:
............(2)
Now equating equation 1 and 2, we get:





Thus, the number of text messages that will result in the exact same charge from both companies is, 500