Question

what is the value of the expression below when z = 2?
3z² - 5z + 9

Explanation:

Step1: Substitute \( z = 2 \) into the expression

Substitute \( z = 2 \) into \( 3z^2 - 5z + 9 \), we get \( 3\times(2)^2 - 5\times2 + 9 \).

Step2: Calculate the power

First, calculate \( (2)^2 = 4 \), so the expression becomes \( 3\times4 - 5\times2 + 9 \).

Step3: Perform multiplication

Calculate \( 3\times4 = 12 \) and \( 5\times2 = 10 \), then the expression is \( 12 - 10 + 9 \).

Step4: Perform addition and subtraction

First, \( 12 - 10 = 2 \), then \( 2 + 9 = 11 \).

Answer:

11