Respuesta :

Answer:

Hey there!

a.

50=28.10+0.15m

Subtract 28.10

21.90=0.15m

Divide by 0.15

m=146

Jacob can send 146 messages.

b.

50=36.50+0.10m

Subtract 36.50

13.5=0.10m

Divide by 0.10

m=135

Roberto can send 135 messages.

Let me know  if this helps :)