Answer: she sent 111 text messages in that month.
Step-by-step explanation:
The equation representing Ms. Thompson's total monthly call phone bill "b" is expressed as
b = 45.60 + 0.10t,
Where
"t" represents the number of text messages she made.
Therefore, the number of text messages that she made in a month in which the total charge was $56.70 is
56.7 = 45.60 + 0.10t
0.1t = 56.7 - 45.6
0.1t = 11.1
t = 11.1/0.1 = 111
