ANSWER
C. 210
EXPLANATION
The given binomial expression is
Comparing to the general binomial expression,
we have
Since we want to find the coefficient of
Using the binomial theorem, the coefficient is
The correct choice is C.
Problem 2
The figure has one line of symmetry.
This line is vertical and passes through the direct center. Imagine folding one side to have it land perfectly on the other side.
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Problem 3
The letter Z has rotational symmetry.
If we were to look at the letter, close our eyes, and then rotate it 180 degrees (or have a friend do so), we wouldn't see any difference if we opened our eyes again. The "before" and "after" images being identical is what gives it rotational symmetry. Put another way, rotating the letter 180 degrees has it line up with itself.
The probability is 100% because all pencils were yellow
The answer is -8 (-8=2*-4)
320/8= 40
40x3= 120
120 students are left handed