Answer correctly ill give brainlist if right : d

Use the Pythagorean theorem:

30^2 + 40^2 = X^2

900+ 1600 = x^2

X^2 = 2500

x = √2500

x = 50

The answer is 50 feet.

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.  

-2x + 7 = 7

subtract 7 from both sides.

-2x = 0

divide both sides by -2.

x = 0