Question

Joel is designing a ramp for a bike trick. He draws this diagram. What is the value of x?

Answer 1

Answer:

x = -1

x = 5

Step-by-step explanation:

Use pythagorean theorem: a² + b² = c²

x² + (2x + 2)² = (2x + 3)²

Since these are quantities, you'll have to make them into quadratic equations.

(2x + 2)(2x + 2) = 4x² + 4x + 4x + 4

(2x + 3)(2x + 3) = 4x² + 6x + 6x + 9

x² + 4x² + 4x + 4x + 4 = 4x² + 6x + 6x + 9

Combine like terms

5x² + 8x + 4 = 4x² + 12x + 9

Move one side to set the equation equal to 0

x² - 4x - 5 = 0

Solve

x² - 5x + x - 5 = 0

x(x - 5) + 1(x - 5) = 0

(x + 1)(x - 5) = 0

x = -1, 5

We can check that these are correct by plugging them in for x and seeing if they are equal

For example

(-1)² + (2(-1) + 2)² = (2(-1) + 3)²

1 = 1