Which is an example of the associative property? a) x + 5 = 5 + x b) (x + 3) + 7 = x + (3 + 7) c) 3 • (x + 5) = 3 • x + 15 d) if x = a, and a = 7, then x =

The first thing we are going to do to solve the problem is to define what associative property is:
 Associative property Property that is fulfilled if, given any three elements of a given set, it is verified that there is an operation that verifies equality
 An expression that meets the definition is:
 (x + 3) + 7 = x + (3 + 7)
 We observe that both members of equality are identical, but written in different ways.
 
 B) (x + 3) + 7 = x + (3 + 7)

Answer: d. 39 cmin the diagram, the approximate length of the minor arc de is 39 centimetres.step-by-step explanation: the formula for the length of an arc in a circle is as displayed below.let the length of the minor arc de = xx = 2( pi )r × angle of sector / 360°from this, we will substitute the values given from the problem into the formula to obtain the length of the minor arc de.x = 2( pi )r × angle of sector / 360°r = radius = 25cmpi as an approximate value = 3.14angle of sector = 120°x = 2( 3.14 )( 25 ) × 120° / 360°x = 157 × 1 / 4x = 39.25x = 39 ( rounded to the nearest whole number as an approximate value )