What’s the answer to this?

or

step-by-step explanation:

we need to solve for 'x' the following equation:  

we have that:

⇒

⇒ ⇒

factorizing, we get that:

  ⇒

then, the solutions are: or

nothing extraneous has been found!

the weight of the object inside the box!

in the simple case, the two triangles point x and y are congruent because every corresponding side has the same length, and every corresponding angle has the same measure.