well...
x^2 is
(x - 3)^2
= (x-3)(x-3)
= x^2 -3x -3x +9
= x^2 - 6x + 9
So... does that help you?
Look back at what the question says... then use my hint.
If x is positive, and x is decreased by 3, then a^2 - x^2 is
a) increased by 6x-9
b) increased by 6x
c)decreased by 9
d)increased by 6x+9
e)decreased by 6x-9
2 answers
well, a^2-(x-3)^2 = a^2-x^2+6x-9, so ...
1 answer