Question

Write the coefficient of y in the expression of (5-y)²

Answer 1

Step-by-step explanation:

${(5 - y)}^{2} = {(a - b)}^{2} \\ = {(a)}^{2} - 2 \times a \times ( - b) + {( - b)}^{2} \\ = {(5)}^{2} - 2(5)( - y) + {( - y)}^{2} \\ = 25 - ( - 10y) + y \\ = 25 + 10y + y \\ = 25 + 11y \\ \\ \\ therefore \: coefficient \: of \: y \: is \: 11$