Problem 1:
Carry out the indicated operations from left to right.
18 divided by (-2/3) * 4 divided by (-7) * (-3) divided by (1/4), but note that anything inside parentheses MUST be done first.
18 div. by (-2/3) could be evaluated by inverting (-2/3) and then multiplying:
18(-3/2) = -27.
Next, multiply this -27 by 4: result is -108.
Divide this result by -7. result: 108/7.
Mult. this result by -3: -324/7
Last, divide this last result by (1/4):
-324
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7 -324 4
------------ = --------- * ------ = -1296/7, or -185 1/7
1 7 1
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4