a) \( 150+5 \cdot 20 \)

Did you know that the order of operations, often remembered by the acronym PEMDAS (Parentheses, Exponents, Multiplication and Division, Addition and Subtraction), plays a crucial role when evaluating mathematical expressions? In your problem, you have to perform the multiplication first before adding. So, \( 5 \cdot 20 = 100 \), and then you add that to 150 to get a grand total of 250! In real-life situations, this principle is just as valuable! When splitting costs at a restaurant or calculating discounts during shopping, understanding how to order your operations can save you time and avoid errors. For example, if you are splitting a final bill that includes tax, you'll want to multiply the tax rate by the subtotal first before doing any additions or subtractions. This will give you the correct final amount.