How can (a+3)2=a2+6a+9 be derived from the polynomial identity (a−3)2=a2−6a+9? A. Add 12a to both sides of (a−3)2=a2−6a+9.
B. Add 6 to both sides of (a−3)2=a2−6a+9.
C. Multiply both sides of (a−3)2=a2−6a+9 by −1.
D. Substitute −a for a on both sides of (a−3)2=a2−6a+9.

Use the elimination method to solve the systems of equations. choose the correct ordered pair. 7x+4y=39

Which expression represents the total perimeter of her sandwich, and if x = 1.2, what is the approximate length of the crust?

At the beginning of the year, adrian's savings account balance was \$28$28. each week, he deposits another \$15$15 into that account, and he doesn't spend any of his savings. is his savings account balance proportional to the number of weeks since the start of the year?