B = 12 * 5 = 60
60 is the answer
The answer is 784
...................................
Its the second choice down. x is an element of the intersection of B and C. A is not part of that, and since B and C overlap, it's the intersection, not the union (U).
5x⁴ - 3x³ + 6x) - (3x³ + 11x² - 8x)<span>
</span>Expand the second bracket by multiplying throughout by -1
5x⁴ - 3x³ + 6x - <span>3x³ - 11x² + 8x
</span>
Group like terms and simplify
5x⁴ - 3x³ - 3x³ - 11x² + 6x <span>+ 8x
</span>5x⁴ - 6x³ - <span>11x² + 14x</span>