Calculate the value of the expressions: 45 \cdot 2 - 6 84 : 6 \cdot 2 18 \cdot 15 + 18 \cdot 10 + 5 28 \cdot 9 + 20 \cdot 9 + 8 \cdot 9

Solution:

To calculate the value of the expressions, we will follow the order of operations (parentheses, exponents, multiplication and division from left to right, addition and subtraction from left to right).

• 45 ⋅ 2 - 6
  • 1. Multiplication: 45 ⋅ 2 = 90
  • 2. Subtraction: 90 - 6 = 84
• 84 : 6 ⋅ 2
  • 1. Division: 84 : 6 = 14
  • 2. Multiplication: 14 ⋅ 2 = 28
• 18 ⋅ 15 + 18 ⋅ 10 + 5
  • 1. Multiplication: 18 ⋅ 15 = 270
  • 2. Multiplication: 18 ⋅ 10 = 180
  • 3. Addition: 270 + 180 = 450
  • 4. Addition: 450 + 5 = 455
• 28 ⋅ 9 + 20 ⋅ 9 + 8 ⋅ 9
  • We can use the distributive property here: (28 + 20 + 8) ⋅ 9
  • 1. Addition within parentheses: 28 + 20 + 8 = 56
  • 2. Multiplication: 56 ⋅ 9 = 504

Answer: 84, 28, 455, 504