Final answer:
To simplify the expression (3x+1) + (-7x+9), combine the like terms and add the coefficients and constant terms separately. The simplified expression is -4x + 10.
Step-by-step explanation:
To simplify the expression (3x+1) + (-7x+9), we combine like terms. The like terms are the terms that have the same variable and the same exponent. In this case, the like terms are 3x and -7x. By adding their coefficients, we get -4x. Similarly, the constant terms 1 and 9 can be added to get 10. Therefore, the simplified expression is -4x + 10.
Learn more about Combining like terms in an algebraic expression