What is the factored form of x2 + 4xy – 21y2? A. xy(x + 4 – 21y)
B. (x – 3y)(x + 7y)
C. x(x + 4y) + y(4x – 21y)
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D. (x + 3y)(x - 7y)

Describe the possible echelon forms of the standard matrix for a linear transformation t where t: set of real numbers is onto.

(mc 02.03) what set of reflections and rotations would carry rectangle abcd onto itself? reflect over the y-axis, reflect over the x-axis, rotate 180° rotate 180°, reflect over the x-axis, reflect over the line y=x reflect over the x-axis, rotate 180°, reflect over the x-axis rotate 180, reflect over the y-axis, reflect over the line y=x

The answer is 7.2 how would you put this as money