Assume that the other number is y.
we know that the addition of both number is -9
this means that:
x+y=-9
reorder this equation to seperate the y variable:
y=-9-x
All your answers look good!
You would divide 8 3/4 by 50 to find out how many cups you would get for just one cupcake. So you would do 8 3/4 DIVIDED BY 50= 0.175 which means there will be 0.175 cups of sugar per cupcake.
I multiply 1200 times 5 and yet 6000 because it says what is the height