B words used in ways that make their precise common meaning clear
Can you explain with a little more details?
3x + 7 = x - 15
First, make sure to subtract

from both sides.
Second, simplify 3x - x to get 2x, and then keep the 7.
Third, subtract

from both sides.
Fourth, simplify -15 - 7 to get -22.
Fifth, take the 2 and divide both sides by it, keeping the

by itself.
Sixth, since 11 goes into 2 to get 22, simplify the fraction to 11.

Answer:
x = -11
we know that
A kenning is a figurative expression that substitutes a name or a noun. It is usually a compound of two words and words have scripts. The Kennings are associated with the poetry of the ancient Norse, Icelandic and Anglo-Saxon.
Examples
First Lady - wife of the president
Four-eyes = someone who wears glasses
therefore
the answer is the option
A) a kenning.