200 min / $10.00 = 20 minutes / dollar
<span>300 min / $12.00 = 25 minutes / dollar </span>
<span>The cost of the 300 minute card is cheaper per minute and a better value. </span>
<span>If you don't expect to use more than 200 minutes then save your money and buy the smaller card.</span>
<em>f(d)=86,400·d</em>
if you set 1 day (d=1) you get f(1)=86,400 sec
if you set 1 day (d=2) you get f(2)=172,800 sec
...etc.
whatttttttt? i have no idea what that is
All you have to do, is combine like terms. Let's go through it:

Arrange it so you can easily combine like terms:

So, your answer for the sum is 1) 7x² - 10x + 2
Answer:
7x - 5y = -5 this is the standard form