[tex](1 - 3k) + (2 + 2.5k)[/tex]
[tex] = 1 - 3k + 2 + 2.5k[/tex]
[tex] = (1 + 2) + ( - 3k + 2.5k)[/tex]
[tex] = 3 + ( - 0.5k)[/tex]
[tex] = 3 - 0.5k[/tex]
