2.4=-5y+14.9
We move all terms to the left:
2.4-(-5y+14.9)=0
We get rid of parentheses
5y-14.9+2.4=0
We add all the numbers together, and all the variables
5y-12.5=0
We move all terms containing y to the left, all other terms to the right
5y=12.5
y=12.5/5
y=2+2.5/5
Y=2.5