book Maths Puzzle Numerical Ability

please help with this problem.
Factor completely.

x^2 + 4xy - 21y^2
thanks

Read Solution (Total 0)

book Other Question

I am having more problems i understand now the last one i submitted but i have TWO problems i cant understand
here is one
During one week Dow Jones Industrial average, the most If the length of a living room is 22 feet, what will that length measure in inches on a blueprint whose scale is 1/4 inch to the foot?