Question

Directions: Transform the following equations into standard form.
1. x2 + 2x = -1
2. 4 + x2 = 7x
3. x2 - x = 1
4. x2 + 9x = 10
5. 4x + 3 = x2
6. x2 + 5x +5
7. 2x5 + 7x = 3x
8. x2 = 3x + 8
9. x(x + 3) = 1
10. x2 - 3x = -2
11. y2 - 7y = -6
12. z2 - 5z = -4

Answer 1

The standard form is:

• ax² + bx + c = 0

Convert each equation:

1. x² + 2x = -1                        add 1 to both sides

⇒ x² + 2x + 1 = 0

2. 4 + x² = 7x                        add - 7x to both sides and rearrange

⇒ x² - 7x + 4 = 0

3. x² - x = 1                            add - 1 to both sides

⇒ x² - x - 1 = 0

4. x² + 9x = 10                       add - 10 to both sides

⇒ x² + 9x - 10 = 0

5. 4x + 3 = x²                        add -4x - 3 to both sides

⇒ x² - 4x - 3 = 0

6. x² + 5x = 5                        add -5 to both sides

⇒ x² + 5x - 5 = 0

7. 2x² + 7x = 3                      add -3 to both sides

⇒ 2x² + 7x - 3 = 0

8. x² = 3x + 8                        add -3x - 8 to both sides

⇒ x² - 3x - 8 = 0

9. x(x + 3) = 1                         distribute and add - 1 to both sides

⇒ x² + 3x - 1 = 0

10. x² - 3x = -2                       add 2 to both sides

⇒ x² - 3x + 2 = 0

11. y² - 7y = -6                        add 6 to both sides

⇒ y² - 7y + 6 = 0

12. z² - 5z = -4                       add 4 to both sides

⇒ z² - 5z + 4 = 0