Answer:
9. the first one ( 12 + 4 = 4 + 12 )
Step-by-step explanation:
the commutative property of addition means that you can change the order of the numbers you add and the sum will still be the same. this is shown in the 12 + 4 = 4 + 12 because the order is switched, but they are still equal.
Answer:
149-1
Step-by-step explanation:
if you did 149-1 you'd get 148
Answer:
6x^2 - 4y^2 + 2x^2 + 6xy
Step-by-step explanation:
Each of the adjacent sides of the rectangle has a congruent, opposite sides. The perimeter is the sum of the lengths of the 4 sides.
P = 2(3x^2 - 2y^2) + 2(x^2 + 3xy)
P = 6x^2 - 4y^2 + 2x^2 + 6xy