Given :
Service cost , c = $40.
Amount paid for each message , m = $0.02 .
To Find :
Equation represents the total cost C in dollars for a month when eric send t text message.
Solution :
Let , total cost be C .
It is an linear equation with slope equal to 0.02 and y-intercept equal to 40.
So ,
Hence, this is the required solution.
I'm assuming that you mean
because if you meant
then u would simplify and you couldn't make it the subject.
Under this assumption, we start with
We multiply both sides by
We expand the left hand side:
We move all terms involving u to the left and all terms not involving u to the right:
We factor u on the left hand side:
We divide both sides by