You will have to form the equation:
1.01+.09x=9.56 Solve for x. Start buy subtracting 1.01 from both sides.
.09x=8.55 Divide both sides by .09
x=95 The call was 95 additional minutes. So...
25+95=120 120 minutes in total. Check your answer by substituting x...
1.01+.09(95)=9.56
1.01+8.55=9.56
9.56=9.56
I hope this helps!