Find the sum. Write the addition property you used. 28+29+42=

Step-by-step explanation:

First your gonna brake up each number and seperate them for example

28

29

42

then your going to add up the ones side, 8,9,2, to get 19.

Then your going to add the tens side, 2,2,4, to get 8.

take the one from 19 and put it in the tens place to get 9 in the tens and 9 in the ones.

put 9 and 9 together to get 99.

Step-by-step explanation:

28+29=57

57+42=99 so 99 should be your answer