Add: a² + b² + c² – 3abc and a² – b² + c² + abc 2. Add: xy² + 4x²y – 7x²y - 3xy² + 3 and x²y + xy²

3. Add: 5x² + 7y - 6z² ; 4y + 3x² ; 9x² + 2z² - 9y and 2y - 2x².

4. From the sum of 3x - 2y + 4z and 3y – 2z, subtract x - y - z.

5. Subtract a – 2b – c from the sum of 3a – b + c and a + b – 3c.

6. The sum of two expressions is 3x2 + 2xy – y2. If one of them is 2x2 + 3y2, find the other.
7. From the sum of 4b2 + 5bc, -2b2 – 2bc – 2z2 and 2bc + 4c2, subtract the sum of 5b2 – c2 and -3b2 + 2bc + c2.
8. What should be subtracted from 3x + 5y + 9 to get - 2x + 3y + 15?

9. Subtract 2m – 5q + 7 from 4p + 2q and add your result to m2 – 3m3 + m - 1.

10. Subtract 2a2b – 3b2 from 3a2 – 5ab2 + 2b2 and subtract your result from the sum of the two expressions 3ab2 + 5b2 – 2a2b and a2b + 5a2 – 3ab2