Let the number of text messages be represented by X.
Then the total cost of David's cell phone adds up to
Since the total cost of David's phone equals $91.40, we get the following equation.
Subtract 50 on both sides
Divide both sides by 0.45
Therefore David has send 92 text messages.
Then the total cost of David's cell phone adds up to
Since the total cost of David's phone equals $91.40, we get the following equation.
Subtract 50 on both sides
Divide both sides by 0.45
Therefore David has send 92 text messages.