Which property do these belong to; the commutative property, the distributive property, and the associative property?
a - 3x25=(3 x 30)+(3 x 5)= 75
b- 15 x (2 x 4) = (15 x 2) x 4 = 120
c - 30 + 5.2 + 7 = 7+5.2 + 3- = 42.2
d- 5 x 13 = (5 x 10) + (5 x 3) = 65

Average acceleration: i have no idea how to do this.

What is the result of adding the system of equations? 2x+y=4 3x-y=6

Three friends went on a road trip from phoenix, az, to san diego, ca. mark drove 50 percent of the distance. jason drove 1/8 of the distance. andy drove the remainder of the distance. 1. andy thinks he drove 1/4 of the distance from phoenix, az, to san diego, ca. is andy correct? 2. the distance from phoenix, az, to san diego, ca, is 360 miles. how many miles did each person drive? 3. solve the problem. what is the answer in total?