Final answer:
To combine like terms, add or subtract the coefficients. In this case, -2k and -4k can be combined by adding their coefficients to get -6k. The equivalent expression is -6k + 5.
Step-by-step explanation:
To combine like terms, we add or subtract the coefficients of the variables. In this case, the like terms are -2k and -4k. To combine them, we add their coefficients: -2k + (-4k) = -6k. The other term, 5, remains the same. So the equivalent expression is -6k + 5.