Which property is shown here? (-3 + 9) + 1 = -3 + (9 + 1)

Evaluate the expression for the given value of the variable. 5×(h+3) for h=7

Lizette is training for a marathon. at 7: 00 she left her house and ran until 8: 30, then she walked until 11: 30. she covered a total distance of 18 miles. her running speed was six miles per hour faster than her walking speed. find her running and walking speeds in miles per hour.

Atransformation t : (x,y) (x-5,y +3) the image of a(2,-1) is