5+5+5=15 (in money terms you get five dollars then another then another, now you have 15 dollars)
15-5=10 (someone takes away 5 dollars, now you have ten dollars)
10+5+5=20 (but they give you back ten dollars, now you have twenty dollars)
20-5=15 (now they take away five dollars, now you have fifteen dollars)
15+5=20 (but they give you five dollars back, now you have twenty dollars)
20X0=0 (think of the twenty dollars as how much money you have and you want to increase itif you multiplied your total of twenty dollars by two you would have two sets of twenty dollars, which equals forty dollars. if you multiply your twenty dollars by zero you would have zero sets of twenty dollars, hence 20X0=0)
Now for your question. The answer should be 15 because of the order of operations, which goes like this
In an equation, you are supposed to multiply and divide first. So first you solve 5X0, which is 0. So now you are left with...
The next thing you do is add and subtract from left to right.
The people who are answering 15 don't make any sense. If you use order of operations it should be -5. The 5*0 first equals 0 so you are left with 5+5+5-5+5+5-5. Addition comes before subtraction so you have to do 5+5+5 and 5+5+5. Both equal 15 so you are left with 15-15-5. That is -5. To get 15 y'all are doing the the first subtraction sign before you do the rest of the addition signs...