1. 0.67 this one does not belong - -2. 0.004 3. 0.2
As with any linear equation of this sort, divide by the coefficient of the variable.
.. 470 h = 3008
.. (470 h)/470 = 3008/470
.. h = 3008/470 = 6.4
If you have

as your cost,
and you paid

,
then

.
Thankfully, most cellphone companies don't charge for minutes anymore!