M-5-(-12) would equal m+7 because there is a negative before the parentheses and in the parentheses which means you would change it to a positive so, negative 5 plus positive 12 is 7 and since the 7 is positive you would add m (hope this helped)
So, personally I would take 252 and divide it by 4. this will give you 63 which is 1/4 of the cookies. Then add that 63 three times to get a total of 189 cookies which would be your 3/4 sold. so since there is only 63 cookies left then you would go into your final problem. 3/9 is equal to 1/3, so all you would do is divide 63 by 3 and get a total of 21 cookies given to the pta.
Well, all you would do is multiply them all together. When multiplying decimals all you have to do to it is move it two places to the left and multiply.
So you would get $630
Hope this helps
