Please can someone help. ill give brainliest

Step-by-step explanation:

upper left angle and lower right are the same in a parallelogram (the other two angles match as well, but aren't useful)

so we can write this equation:

3x -15 = 2x +24

1x -15 = 24

x = 39

always do the same thing on both sides of an equation (here: subtract 2x, then add 15)

now you might give it a try yourself with the next problem that got two same things in it.

always grow stronger :)

step-by-step explanation:

descending order means to order the polynomials from the term with the largest exponent to the term with the smallest exponent.  

therefore, the correct answer is d.