The three refers to 3 ten thousands. or 3 x 10,000.
For this case, the first thing you should do is define a variable.
We have then:
t: temperature (degree Fahrenheit).
We write then the inequation that adapts to the problem:
t> = 451
Answer:
an inequality that is true only for temperatures at which books spontaneously catch on fire is:
t> = 451
Sender would be 4 x 7 divided by 15
Answer: D
Dependent variable is Distance.