these numbers form an addition and subtraction fact family 1,2,3 choose the fact family formed by these numbers I got c 3-1=2 2+1=3 3-2=1 1+2=3 that's what I got

It's like discovering the answer to a puzzle. the purpose in solving an equation is to find the value or values of the variable that makes it a true statement. any value of the variable that makes the equation true is called a solution to the equation.