Simplify each expression.
Remember to line up the decimal points when adding or subtracting numbers with decimals.
When you subtract a negative, you add its opposite.
Find a common denominator.
See part (b).
Multiply the numerators together and the denominators together.
When you multiply numbers with decimals, you do not necessarily have to line up the decimal points.
Remember, a negative number multiplied by a positive number is always a negative number.