1. 3X_=1+2=_?
The initial question does not really make total sense, since it is say 3 times some number equals 3, which also equals that same number. If I let y = "some number"
3Xy=1+2= y
3Xy=3=y
dividing by y
3 = 3/y = 1
There is no answer, since y=3 will make the right part correct, but not the left side.
I *think* the question is asking 3X_=1+2, solve for _
Letting y=_
3Xy=1+2
3Xy=3
Divide each side by 3
1Xy=1
y=1
_=1
Answer checks out.
2. 4+1=_X6=_?
4 + 1 = yX6
5=yX6
divide each side by 6
5/6 = yX1
y = 5/6
3. 22-__=20+1X1=_?
22 - y = 20 + 1X1
simplify right side
22 - y = 20 + 1
22 - y = 21
subtract 22 from both sides
(22 - 22) - y = 21 - 22
0 - y = -1
-y = -1
divide both sides by -1 to remove the -1 sign
-y/-1 = -1/-1
y = 1