Find the Intersection Points: Solve the Quadratic y=(4x+8)(x+1)

Question

Determine the points of intersection of the function

y=(4x+8)(x+1) y=(4x+8)(x+1)

With the X

Video Solution

Solution Steps

00:00 Find the intersection points with the X-axis
00:03 At the intersection points with the X-axis, the Y value must = 0
00:07 Substitute Y = 0 and solve to find X values
00:13 Find what makes each factor in the product zero
00:18 This is one solution
00:39 This is the second solution
00:45 And this is the solution to the question

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Set the function y=(4x+8)(x+1) y = (4x + 8)(x + 1) equal to zero, i.e., (4x+8)(x+1)=0 (4x + 8)(x + 1) = 0 .
  • Step 2: Apply the zero-product property to resulting factors.
  • Step 3: Solve each equation for x x .

Now, let's work through each step:
Step 1: We start by setting the equation to zero:
(4x+8)(x+1)=0(4x + 8)(x + 1) = 0.

Step 2: Using the zero-product property, we find:
1. 4x+8=04x + 8 = 0
2. x+1=0x + 1 = 0

Step 3: Solve each of these equations for x x :

For 4x+8=04x + 8 = 0, subtract 8 from both sides to get 4x=84x = -8. Divide both sides by 4, resulting in:
x=2x = -2.

For x+1=0x + 1 = 0, subtract 1 from both sides to get:
x=1x = -1.

Thus, the points of intersection of the function with the x-axis are the solutions we just found. At these points, the y-value is zero, giving us the intersection points as (1,0)(-1, 0) and (2,0)(-2, 0).

Therefore, the solution to the problem is (1,0),(2,0)(-1, 0), (-2, 0).

Answer

(1,0),(2,0) (-1,0),(-2,0)