In the expression \( 3x - 4 + x + 7 \), we can identify the like terms.
The like terms are:
- \( 3x \) and \( x \) (both are terms with the variable \( x \)).
- \( -4 \) and \( 7 \) (both are constant terms).
So the correct pairs of like terms are:
- 3x and x
- −4 and 7
The other options (3x and -4, x and -7) are not pairs of like terms.
Thus, the pairs of like terms in the expression are:
- 3x and x
- −4 and 7