B. Perform the following operations on polynomials. 1. (2x + 3y) - (5x – 2y)
2. (9x²y + 5xy - 2) + (-12x²y – 3xy + 2)
3. (8x + 2y - 3z") + (42* - 5x + 3y)
4.(- 10x*yz? + 5xyz-2) -(10xyz + x - 10 xy)
5. (3x + y) - (2x + z)
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Which approach to the theory-and-research cycle does the following sequence reflect: (1) specific observations suggest generalizations, (2) generalizations produce a tentative theory, (3) the theory is tested through the formation of hypotheses, and (4) hypotheses may provide suggestions for additional observations?

What is sin 7x/4 ? i need on this urgent trig

Points a, b, and c form a triangle. complete the statements to prove that the sum of the interior angles of triangle abc is 180