First let's find the result of the sum:
30 + 40 + 70 = 140
Now let's review the operations of each one:
Jillian added 30and40and then 70:
30 + 40 = 70
70 + 70 = 140
Samuel added 30 and 70 and then 40
30 + 70 = 100
100 + 40 = 140
answer
both are correct.
Conclusion: the order of the factors does not alter the product.
