Three more than 1 is equal to 4.

Twice 1/2 is 1.

The number is 1/2.

Check

3 + 2(1/2) = 4

3 + 1 = 4 (yes)

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If you insist on writing an equation, rather than solving it the way you could in 2nd grade, here goes ...

3+2x = 4

2x = 1 (subtract 3 from both sides. Does this look familiar?)

x = 1/2 (divide both sides by 2)

Twice 1/2 is 1.

The number is 1/2.

Check

3 + 2(1/2) = 4

3 + 1 = 4 (yes)

_____

If you insist on writing an equation, rather than solving it the way you could in 2nd grade, here goes ...

3+2x = 4

2x = 1 (subtract 3 from both sides. Does this look familiar?)

x = 1/2 (divide both sides by 2)