Question

if the figure is a rectangle, the value of x is...

Explanation:

Step1: Recall the property of rectangle diagonals

In a rectangle, the diagonals are equal in length. So, \(10x + 8=9x + 20\).

Step2: Solve the equation for \(x\)

Subtract \(9x\) from both sides: \(10x-9x + 8=9x-9x + 20\), which simplifies to \(x+8 = 20\).
Then subtract \(8\) from both sides: \(x+8-8=20 - 8\).

Answer:

\(x = 12\)