I speak without a mouth and hear without ears. I have nobody but come alive with the wind. What am I?

An echo

The answer to the above riddle is, "An echo." An echo is a reflection of your own voice. Which is why an echo can 'speak without a mouth and hear without ears'. However, an echo is only heard when the wind conditions are optimal, so it 'comes alive with the wind'.

An echo

Step-by-step explanation:

hope it helps!

step-by-step explanation:

we are given

since, we have to isolate x on anyone side

so, we can move all x terms on one side

subtract both sides by 2x

add both sides by 9

divide both sides by 4

we get

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.