Question

3. What must be added to 1 - 2x + 3x² to obtain 3+ 5x - 7x².
4. What must be subtracted from -4m² + 5m - 3 to obtain m² - 3m.
5. From the sum of 4b² + 5bc, -26²-2bc - 2z² and 2bc + 4c². subtract the sum of 5b² - c² and -3b² + 2bc + c².​

Answer 1

Please see attachments.

Answer 2

Explanation:

3).

→ (3 + 5x - 7x²) - 1 - 2x + 3x²

→ 2 + 3x - 4x²

therefore, 2 + 3x - 4x² must be added to 1 - 2x + 3x² to obtain 3 + 5x - 7x².

4).

→ ( -4m² + 5m - 3 ) + m² - 3m

→ -3m² + 2m - 3

therefore , -3m² + 2m - 3 must be subtracted from -4m² + 5m - 3 to obtain m² - 3m.

hope this answer helps you!