Find the value of x in the rhombus

Question

Here are the two angles 6x²-18 Then 5x²-7x

Answer 1

In a Rhombus, consecutive angles are supplementary and opposite angles are congruent. Looking at the two equations, I'm guessing these angles are opposite angles. So set them equal and solve for x:

6x² - 18 = 5x² - 7x

x² + 7x - 18 = 0

(x+9)(x-2) = 0

x = -9 and 2