Identify what property ( commutative identity distributive, or associative) is used.

a. y• 7 = 7y

b. 3y + (7+2y) = (3y +7) + 2y

c. y + 0 = y

d. 2 (x + 5 ) = 2x + 10

; _;

C is identity 

B is associative 

A is identity

B is communitative

1. isolate the variable, in this case, d. subtract 35.5 on both sides of the equation.2. 52 subtracted by 35.5 is 16.53. therefore your answer would be d= 16.5this is the basics of pre algebra, isolating variable through adding, subtracting, multiplying, and dividing, if you have any other questions to ask just comment!