1. 100 minus 5 times a number
2.0.25 multiplied by a number plus 0.6 multiplied by a number
3. 3 times m minus 8 times n divided by 13
Substituting <em>x</em> with <em>π</em>/2 - <em>x</em> gives the equivalent integral,

So if we let <em>J</em> denote the value of the integral, we have



Condensing the logarithms, we have
log(tan(<em>x</em>)) + log(cot(<em>x</em>)) = log(tan(<em>x</em>) cot(<em>x</em>)) = log(1) = 0
since cot(<em>x</em>) = 1/tan(<em>x</em>), which means

and so the original integral has a value of <em>J</em> = 0.
Answer:
you did not supply enough information
Hi there!
Inequality:
25 - 0.75x <= 13
Since x is the amount of MP3 downloads he can buy and each CD costs 0.75 dollars, and since the total price spent needs to be less than 13 dollars and the total amount of money he has is 25 dollars, this is the answer.
Hope this helps!