Answer: 12 texts per dollar.
The slope of the line is 1/5
Step-by-step explanation: If Ruby can send 48 text messages for $4, we divide 48 by 4 to get amount of texts per dollar: 12. Ruby can send 12 text messages for $1.
To figure out the slope of a line, use the formula y2 - y1 / x2 - x1.
-4 - (-9) / 22 - (-3) = 5 / 25 (rise over run)
Simplify to 1/5