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Find both points of intersection between the graphs of the functions:

f(x) = (x + 5) (x – 4)
g(x) = x +5

User Dominique
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1 Answer

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Final answer:

To find the points of intersection between the graphs of f(x) and g(x), set f(x) = g(x) and solve for x. The solutions are x = -5 and x = 4. Substitute these values back into either function to find the corresponding y-values, yielding the intersection points (-5, 0) and (4, 9).

Step-by-step explanation:

To find the points of intersection between the graphs of the functions f(x) = (x + 5)(x – 4) and g(x) = x + 5, we need to set them equal to each other and solve for x. This is because at the points of intersection, both functions will have the same y-value (the dependence of y on x is the same for both functions).

Setting f(x) equal to g(x):

(x + 5)(x - 4) = x + 5

Expanding f(x):

x^2 + 5x - 4x - 20 = x + 5

Combining like terms:

x^2 + x - 20 = x + 5

Subtracting x + 5 from both sides:

x^2 - 20 = 0

Factoring the quadratic equation:

(x + 5)(x - 4) = 0

Setting each factor equal to zero gives us two solutions:

x + 5 = 0 or x - 4 = 0

Thus, x = -5 or x = 4.

To find the corresponding y-values, we substitute these x-values back into either original function (using g(x) for simplicity):

For x = -5: g(-5) = -5 + 5 = 0

For x = 4: g(4) = 4 + 5 = 9

Therefore, the points of intersection are (-5, 0) and (4, 9).

User Gary Howlett
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