The diagonals of rhombus FGHJ intersect at point C. If side GH is equal to x + 9 and side JH is equal to 5x – 2, find x.

a rhombus is a a quad with 4 equal sides.

So if you have followed the convention of naming the vertices in either a clockwise or couter-clockwise fashion, then both GH and JH are sides of the rhombus

so 5x-2 = x+9
4x = 11
x = 11/4 = 2.75

The fact that the diagonals intersect at C appears redundant information.

To find the value of x, we can set up an equation using the given information about the sides of the rhombus.

In a rhombus, the diagonals bisect each other at right angles. This means that the lengths of the diagonals are equal. Let's denote the length of the diagonal FH as d1 and the length of the diagonal GJ as d2.

Using the Pythagorean theorem, we can relate the sides of the rhombus to the diagonals:

d1^2 = (GH/2)^2 + (JH/2)^2

Substituting the given side lengths, we have:

d1^2 = ((x + 9)/2)^2 + ((5x - 2)/2)^2

Similarly, we can set up an equation using the other diagonal:

d2^2 = (HG/2)^2 + (HJ/2)^2

d2^2 = ((x + 9)/2)^2 + ((5x - 2)/2)^2

Since the diagonals are equal, we can set these two equations equal to each other:

((x + 9)/2)^2 + ((5x - 2)/2)^2 = ((x + 9)/2)^2 + ((5x - 2)/2)^2

Next, we can simplify this equation:

(x + 9)^2 + (5x - 2)^2 = (x + 9)^2 + (5x - 2)^2

Expanding the squared terms:

(x^2 + 18x + 81) + (25x^2 - 20x + 4) = (x^2 + 18x + 81) + (25x^2 - 20x + 4)

Combining like terms:

x^2 + 18x + 81 + 25x^2 - 20x + 4 = x^2 + 18x + 81 + 25x^2 - 20x + 4

Simplifying further:

26x^2 - 2 = 26x^2 - 2

The 26x^2 terms cancel out, leaving us with:

0 = 0

This equation is always true, regardless of the value of x. This means that x can be any real number, as long as it satisfies the given side lengths of the rhombus. Therefore, there are infinitely many possible values for x that would satisfy the conditions of the problem.