Question

(4,5 y +9)-(6,2-3,1y) = 7,2y-2,8​

Answer 1

$(4.5y + 9) - (6.2 - 3.1y) = 7.2y - 2.8 \\ 4.5y + 9 - 6.2 + 3.1y = 7.2y - 2.8 \\ 7.6y + 2.8 = 7.2y - 2.8 \\ 7.6y - 7.2y = - 2.8 - 2.8 \\ 0.4y = - 5.6 \\ y = - 5.6 \div 0.4 \\ y = - 14$