Answer:
1. -b^2+13b
2. 1.9y^2-1.4y+4
Explanation:
1. -0.8b^2+7.4b+(5.6b-0.2b^2)
Simplify: -0.8b^2+7.4b+5.6b-0.2b^2
Add like terms: (-0.8b^2-0.2b^2)= -1b^2/-b^2 (7.4b+5.6b)= 13b
Answer: -b^2+13b
2. (7.3y-y^2+4)+0.5y^2-(8.7y-2.4y^2)
Simplify: 7.3y-y^2+4+0.5y^2-8.7y+2.4y^2
Add like terms: (2.4y^2-y^2)= 1.9y^2 (7.3y-8.7y)= -1.4y (don't forget about the 4)
Answer: 1.9y^2-1.4y+4