Answer:
1. The quadratic equation is 3x² +17.5x - 58.5 = 0
2. The values of x are 2.38 and -8.21, but we only take 2.38 for our problem.
3. The dimensions of the combined area are approximately 6.38 inches and 12.64 inches.
Step-by-step explanation:
1. Let's review the information given to us to answer the question correctly:
Photograph dimensions = 4 inches * 6 inches
Frame dimensions = x inches * 3x - 0.5 inches
Area of the combined area of the photograph and the frame = 80.5 inches²
2. Write a quadratic equation for the combined area. Then use the quadratic equation formula to find x.
One side of the combined area of the photograph and the frame = 4 + x inches
Second side of the combined area of the photograph and the frame = 6 + 3x - 0.5 inches
Now, we can write the quadratic equation this way:
Combined area of the photograph and the frame = One side * Second side, replacing with the values we know:
80.5 = (4 + x) * (6 + 3x - 0.5)
80.5 = (4 + x) * (5.5 + 3x)
80.5 = 22 + 5.5x + 12x + 3x²
3x² +17.5x - 58.5 = 0
Using the quadratic formula, where, a = 3, b = 17.5 and c = - 58.5, we have:
x = (-b +/- √b² - 4ac)/2a
x = (-17.5 +/- √17.5² - 4 * 3 * -58.5) 2 * 3
x = (-17.5 +/- √306.25 + 702)/6
x = (-17.5 +/- √1,008.25)/6
x = (-17.5 +/- 31.75)/6
x₁ = 14.25/6 = 2.38
x₂ = -49.25/6 = -8.21
We took the value of x₁ because x₂ is negative and we can't have a negative value for the length or the width, therefore:
80.5 = (4 + x) * (5.5 + 3x)
Replacing x, we have:
80.5 = (4 + 2.38) * (5.5 + 3 * 2.38)
80.5 = 6.38 * 12.64
80.5 ≅ 6.38 * 12.64
