"seven" means ' 7 '
"two" means ' 2 '
"the quantity seven plus two" means ' (7 + 2) '
"one hundred times the quantity ..." means ' 100 (7 + 2) '
That's the expression.
One of the rules for handling these things is that you should always
take care of anything inside parentheses first. So do that.
(7 + 2) = 9
Now you can can write the expression like this: ' 100 (9) ' .
That's just 900 .
