Answer:
1. Absolute value : d. | - 7| = 7
2. All real numbers : b. 3x = 3x
3. x = -5 : c. 5x = -25
4. No solution : a. |2x| = -10
5. Adding the opposite to both sides of the equation. : e. Canceling
Explanation:
1. Absolute value : d. | - 7| = 7
The absolute value is considered the distance to 0... so if there's a negative sign in the value, the negative sign disappears.
2. All real numbers : b. 3x = 3x
If we divide both sides by 3, we have x = x, which will always be true.
3. x = -5 : c. 5x = -25
If we multiply each side by 5, we have 5(x) = 5(-5) thus 5x = -25
4. No solution : a. |2x| = -10
The result of an absolute value cannot be a negative number. So, that has no solution since there's no value of x that would make this true.
5. Adding the opposite to both sides of the equation. : e. Canceling
If you have for example (x = -5) and you add 5 on both sides, you cancel the value on the right side... (becomes x + 5 = 0).