Answer:
You can send 160 test messages.
Explanation:
I'm assuming this is for algebra so I'll exlain it algerbraicly.
First you have to set up the equation: 26+.15x=50
x is the amount of text messages you can send
Now you try to get x alone. You start by subtacting 26 from both sides: .15x=24
Finally you divide both sides by .15 and you get x=160