$$ {a^2-b^2-2bc-c^2}\over{a^2+b^2+2ab-c^2}$$ is equal to

What is the slope of the line perpendicular to the line passing through the points (-5, 1) and (-2, 0)? 

Direction: Study the information given below carefully and answer the questions given below.
There are 450 coupons which can be used in Pedicure and Hair cutting. Ratio between Males to Females who use their coupons in Hair cutting is 13: 7 Number of males who use their coupons in Pedicure is 72 more than number of females who use their coupon in Hair cutting. Total number of males who use their coupon in Pedicure and Haircutting together is 174 more than total number of females who use their coupon in Pedicure and Haircutting together.

Males who use their coupons in Pedicure what percent of the Males who use their coupons in Haircutting? 

The east positive integer that should be subtracted from 3011 x 3012 so that the difference is a perfect square is-

If the numerator of a fraction is increased by 250% and the denominator is increased by 400%. The resultant fraction is7/19 . What is the original fraction?

If $${a+b=10}$$ and $$ \sqrt{a\over b}-13=-\sqrt{b\over a}-11$$, then what is the value of $${3ab+4a^2+5b^2}$$?

A, B, and C alone can do a work in 40 days ,120 days and 36 days respectively. A and B work together for 20 days and leave it incomplete. C carries on the work and complete it alone.  How many days did C take to complete the work?

If one number is 50 percent less than X and the other numbers are 20 percent less than X. What is the ratio of both the numbers?