In the xy-plane, the graph of y = x² + bx + c, where b and c are constants, has x-intercepts at x = − 2 and x = − 6. What is the value of b?

The correct answer is: 8

Step by step explanation:
Given
Equation: y = x² + bx + c
It has x-intercepts at x = − 2 and x = − 6.
Step 1:
As it is given that, It has x-intercepts at x = − 2 and x = − 6.
This are points where graph cut x-axis.
And points at which graph cut x-axis are roots of equation.
∴ x = − 2 and x = − 6 are roots of y = x² + bx + c
Step 2:
Find sum of roots
x₁ + x₂ = 
⇒ - 2 + (- 6) = 
⇒ - 8 = - b
⇒ 8 = b
Hence, the value of b is 8.