Leonardo wrote an equation that has an infinite number of solutions. One of the terms in Leonardo’s equation is missing, as shown below. Negative (x minus 1) + 5 = 2 (x + 3) minus box

Which could be the missing term that Leonardo put into the box?
x
3x
1
5

Read the excerpt from gilgamesh: a new english version.gilgamesh backed away. he said,"how dreadful humbaba's face has become! it is changing into a thousand nightmarefaces, more horrible than i can bear.i feel haunted. i am too afraid to go on." §enkidu answered, "why, dear friend,do you speak like a coward? what you just saidis unworthy of you. it grieves my heartwe must not hesitate or retreat."