The company charges 15 dollars per month for first 300 text messages and thereafter 0.08 dollars for any additional text message.
It says that we used additional 60 text messages (after fair usage of first 300 messages in the plan).
Our bill for this month would be sum of charges for 300 messages and charges for additional 60 messages.
Total bill = 15 dollars + 60x0.08 dollars = (15 + 4.80) dollars.
Total bill = 19.80 dollars.
Hence, our bill this month would be 19.80 dollars.
<span>For this IF function, look at cell A1. The logical test asks if the value in A1 is less than 100,000: in this case, the value of 90,000 would be less. If the value in A1 is under 100,000, the value is to be multiplied by 0.05 (5%), and multiplied by 0.075 if it is 100,000 or greater (7.5%). For a value of 90,000 * 0.05, the value that would be displayed in the cell with the IF function would be 4,500.</span>
First you have to find the angle B (check attachment)
Then you can find the last angle inside the triangle, which I'll call C
Now you can find angle A
The derivative of f(x) at x=3 is 2x=6 approaching from the left side (apply power rule to y=x^2). The derivative of f(x) at x=3 is m approaching from the right side. In order for the function to be differentiable, the limit of derivative at x=3 must be the same approaching from both sides, so m=6. Then, x^2=mx+b at x=3, plug in m=6, 9=18+b, so b=-9.
