A) He wanted to create zero pairs on the left side of the equation to get a positive coefficient of x on the right side
try it on
https://www.wolframalpha.com it will helpp you for the math problem :)
A function is a special relationship where each input has a single output.
therefore :
A is not a function; x=0; ⇒y₁=3; y₂=4
C is not a function; x=2;⇒ y₁=1; y₂=8
D is not a function; x=1;⇒y₁=2, y₂=-3
only B is a function; each input has a single output.
