Evaluate the expression (a² + b² + c²) − 2(ab + bc) if a= −1, b= −2, and c= −5

Question

Quizplus · Accepted Answer

Step 1: Substitute the numbers into the given expression.
a= −1, b= −2, and c= −5
(a² + b² + c²) − 2(ab + bc)
(−1² + −2² + −5²) − 2(−1 • −2 + −2 • −5)
Step 2: Simplify following the order of operations (PEMDAS):
Parentheses and Exponents
(−1² + −2² + −5²) − 2(−1 • −2 + −2 • −5)
(1 + 4 + 25) − 2(−1 • −2 + −2 • −5)
(30) − 2(2 + 10)
(30) − 2(12)
Multiplication and Division
(30) − 2(12)
30 − 24
Addition and Subtraction
30 − 24 = 6

Evaluate the Expression (A² + B² + C²) − 2(ab