Question 578014
{{{649=600+40+9}}}
It is also sometimes written as
{{{649=6*100+4*10+9}}} or {{{649=6*10^2+4*10+9}}}
The distributive property says that
{{{(600+40+9)*5=600*5+40*5+9*5)}}}
So answer d) is correct {{{highlight(649*5=(600*5)+(40*5)+(9*5))}}}
We really do not need to write the parentheses around each product, because centuries ago it was agreed that it would be understood that the multiplications found between plus and minus signs would be done first. It was a matter of convenience, in order to greatly reduce the number of parentheses to be written, because a common calculation was the total cost of a list of items, which is often calculated as a sum of products. And so the order of operation rules taught at the beginning of algebra class came to be.