SOLUTION: Add suitable numbers to the following expressions to give perfect squares: a) x^2 - 8x b) x^2 - x c) y^2 + 6cy

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Question 957811: Add suitable numbers to the following expressions to give perfect squares:
a) x^2 - 8x
b) x^2 - x
c) y^2 + 6cy
Answer by Edwin McCravy(20054) About Me  (Show Source):
You can put this solution on YOUR website!
Rule:

1.  Multiply the coefficient of x or y or whatever letter, by 1%2F2.
2.  Square the result of step (1).
3.  Add that to the right side.

First one:

a) x^2 - 8x

1.  Multiply the coefficient of x, which is (-8), by 1%2F2, 
getting %28-8%29%281%2F2%29 or -4
2.  Square the result of step (1), getting %28-4%29%5E2, or 16.
3.  Add that to the right side.

Answer: x^2 - 8x + 16

You do the others.

b) x^2 - x

For that one the coefficient of x is (-1).

c) y^2 + 6cy

For that one, the coefficient of y is (+6c), (not just +6).

Edwin