Which of the expressions are equivalent to the one below? (15•3)-20 a. (3-20)•(15-20) b. (3•15)-20 c. 6•(15-20) d. 20-(3•15)

20 ! need which shows a difference of squares? 10y^2-4x^2 16y^2-x^2 8x^2-40x+25 64x^2-48x+9

65 8 7 4 5 6 8 4 3 2 1 9 5 6 4 2 1 6 5 1 5 1 3 2 3 5 multiply the third number in the first row by the seventh number in the third row. add this result to the fifth number in the second row. add to this total ten times the fourth number in the third row. subtract the eighth number in the first row from the result.

Acircle has a circumference of 7.850 units. what is its radius?