pahel need ko ngayun

What is monomials 1.8y²,-5y² find the sum 2.9a²b,-7a²b similar terms 3.-4y,6y answer the following 4.what must added to a obtain 7a

What is the answer? then please add solution then solve it​

Nancy bought 54,945 worth of goods and spent 800 in transporting the goods from divisoria to daet camarines norte. after selling all the goods, she realized a gross profit of 5,575. how much did she sell the goods? ​