Part (a)
Answer: -300 + (-300) + (-300) + (-300)
We have four copies of -300 added together. Use parenthesis to help separate the pluses and minuses.
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Part (b)
Answer: 4*(-300) or -300*4. It multiplies to -1200
Since we add four copies of -300, we can use the shortcut to multiply 4 by -300. Another example of this would be 3+3 = 2*3
The result of 4*(-300) is -1200. Therefore, the Dow Jones has dropped a total of 1200 points.