Respuesta :

thebecks

Answer:

a) -2.5x+3.9+1.7x

circle: 2.5x and 1.7x

variables: x

b) 1 1/2+t+2/3s

no like terms

variables: s and t

c) 15k+2/3k+3m

circle: 15k and 2/3k

variables: k and m