Evaluate the expression (x² − xy + yz) if x = 3, y = −2, and z = −5

Question

Evaluate the expression (x² − xy + yz) if x = 3, y = −2, and  z = −5

Quizplus · Accepted Answer

Step 1: Substitute the numbers into the given expression.
x = 3, y = −2, and  z = −5
x² − xy + yz
3² − (3)(−2) + (−2)(−5)
Step 2: Simplify following PEMDAS:
Parentheses and Exponents. There is nothing to simplify inside of parentheses but we can simplify 3² to 9.
3² − (3)(−2) + (−2)(−5)
9 − (3)(−2) + (−2)(−5)
Multiplication and Division. There is nothing to divide but we have two instances of multiplication to simplify.
9 − (3)(−2) +  (−2)(−5)
9 − (−6) + 10
Addition and Subtraction. We now simplify addition and subtraction from left to right. Remember that subtracting a negative number is the same as adding a positive number.
9 − (−6) + 10
15 + 10
25

Evaluate the Expression (X² − Xy + Yz) If X