Final answer:
To solve math problems, identify the appropriate equation and adhere to rules regarding the signs of numbers when performing calculations. Simplify the algebra where possible and ensure the answer is reasonable. Always check units and round off to the appropriate decimal places.
Step-by-step explanation:
To solve math problems, it is essential to identify the equation to use and follow specific rules for calculations, particularly regarding the signs of the numbers involved. After writing all the given information, we select the appropriate equation. When multiplying or dividing numbers, if they are both positive or both negative, the answer will be positive. If they have opposite signs, the answer is negative. For adding or subtracting, if the numbers are like-signed, keep the sign; if they have different signs, subtract the smaller number from the larger and keep the sign of the larger number. Lastly, it is important to simplify the algebra and check that the answer makes sense.
Rules for Calculation
- Two positive numbers multiplying result in a positive answer.
- Two negative numbers multiplying also give a positive answer.
- Multiplying numbers with opposite signs gives a negative answer.
- Division follows the same sign rules as multiplication.
- Adding two positive numbers results in a positive sum.
- The sum of two negative numbers is also negative.
- When adding numbers with opposite signs, the result takes the sign of the larger number.
- Subtraction can be approached as adding the opposite.
Example
Suppose we have an equation that leads to two values of x, where one value is due to a positive sign and the other a negative sign in the numerator. Often one of these values will not make sense in the context of the problem, and can be disregarded, leaving one viable solution.
Ensuring all values are in correct units and rounding off calculations according to the precision of the least certain value is also a critical step in the process.